Additional feedback for location detection of device-free objects using wireless communication signals

ABSTRACT

Disclosed are techniques for wireless sensing. In an aspect, a user equipment (UE) measures at least a line-of-sight (LOS) path and a non-line-of-sight (NLOS) path of a first downlink positioning reference signal (DL-PRS) from a first transmission-reception point (TRP), measures at least an LOS path and an NLOS path of a second DL-PRS from a second TRP, measures at least an LOS path and an NLOS path of a third DL-PRS from a third TRP, and enables a location of a non-participating target object to be determined based, at least in part, on reference signal time difference (RSTD) measurements between a time of arrival (ToA) of the LOS path of the first DL-PRS and the ToAs of the NLOS paths of the first, second, and third DL-PRS. In an aspect, the non-participating target object does not participate in determining its own location.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Application for Patent claims the benefit of U.S.Provisional Application No. 63/038,019, entitled “ADDITIONAL FEEDBACKFOR LOCATION DETECTION OF DEVICE-FREE OBJECTS USING WIRELESSCOMMUNICATION SIGNALS,” filed Jun. 11, 2020, assigned to the assigneehereof, and expressly incorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks), a third-generation (3G) high speeddata, Internet-capable wireless service and a fourth-generation (4G)service (e.g., Long Term Evolution (LTE) or WiMax). There are presentlymany different types of wireless communication systems in use, includingcellular and personal communications service (PCS) systems. Examples ofknown cellular systems include the cellular analog advanced mobile phonesystem (AMPS), and digital cellular systems based on code divisionmultiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), the Global System for Mobilecommunications (GSM), etc.

A fifth generation (5G) wireless standard, referred to as New Radio(NR), calls for higher data transfer speeds, greater numbers ofconnections, and better coverage, among other improvements. The 5Gstandard, according to the Next Generation Mobile Networks Alliance, isdesigned to provide data rates of several tens of megabits per second toeach of tens of thousands of users, with 1 gigabit per second to tens ofworkers on an office floor. Several hundreds of thousands ofsimultaneous connections should be supported in order to support largesensor deployments. Consequently, the spectral efficiency of 5G mobilecommunications should be significantly enhanced compared to the current4G standard. Furthermore, signaling efficiencies should be enhanced andlatency should be substantially reduced compared to current standards.

SUMMARY

The following presents a simplified summary relating to one or moreaspects disclosed herein. Thus, the following summary should not beconsidered an extensive overview relating to all contemplated aspects,nor should the following summary be considered to identify key orcritical elements relating to all contemplated aspects or to delineatethe scope associated with any particular aspect. Accordingly, thefollowing summary has the sole purpose to present certain conceptsrelating to one or more aspects relating to the mechanisms disclosedherein in a simplified form to precede the detailed descriptionpresented below.

In an aspect, a method of wireless sensing performed by a user equipment(UE) includes measuring at least a line-of-sight (LOS) path and anon-line-of-sight (NLOS) path of a first downlink positioning referencesignal (DL-PRS) from a first transmission-reception point (TRP);measuring at least an LOS path and an NLOS path of a second DL-PRS froma second TRP; measuring at least an LOS path and an NLOS path of a thirdDL-PRS from a third TRP; and enabling a location of a non-participatingtarget object to be determined based, at least in part, on a firstreference signal time difference (RSTD) between a time of arrival (ToA)of the LOS path of the first DL-PRS and a ToA of the NLOS path of thefirst DL-PRS, a second RSTD between the ToA of the LOS path of the firstDL-PRS and a ToA of the NLOS path of the second DL-PRS, and a third RSTDbetween the ToA of the LOS path of the first DL-PRS and a ToA of theNLOS path of the third DL-PRS, wherein the non-participating targetobject does not participate in determining the location of thenon-participating target object.

In an aspect, a user equipment (UE) includes a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: measure at least a line-of-sight (LOS) path and anon-line-of-sight (NLOS) path of a first downlink positioning referencesignal (DL-PRS) from a first transmission-reception point (TRP); measureat least an LOS path and an NLOS path of a second DL-PRS from a secondTRP; measure at least an LOS path and an NLOS path of a third DL-PRSfrom a third TRP; and enable a location of a non-participating targetobject to be determined based, at least in part, on a first referencesignal time difference (RSTD) between a time of arrival (ToA) of the LOSpath of the first DL-PRS and a ToA of the NLOS path of the first DL-PRS,a second RSTD between the ToA of the LOS path of the first DL-PRS and aToA of the NLOS path of the second DL-PRS, and a third RSTD between theToA of the LOS path of the first DL-PRS and a ToA of the NLOS path ofthe third DL-PRS, wherein the non-participating target object does notparticipate in determining the location of the non-participating targetobject.

In an aspect, a user equipment (UE) includes means for measuring atleast a line-of-sight (LOS) path and a non-line-of-sight (NLOS) path ofa first downlink positioning reference signal (DL-PRS) from a firsttransmission-reception point (TRP); means for measuring at least an LOSpath and an NLOS path of a second DL-PRS from a second TRP; means formeasuring at least an LOS path and an NLOS path of a third DL-PRS from athird TRP; and means for enabling a location of a non-participatingtarget object to be determined based, at least in part, on a firstreference signal time difference (RSTD) between a time of arrival (ToA)of the LOS path of the first DL-PRS and a ToA of the NLOS path of thefirst DL-PRS, a second RSTD between the ToA of the LOS path of the firstDL-PRS and a ToA of the NLOS path of the second DL-PRS, and a third RSTDbetween the ToA of the LOS path of the first DL-PRS and a ToA of theNLOS path of the third DL-PRS, wherein the non-participating targetobject does not participate in determining the location of thenon-participating target object.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a user equipment(UE), cause the UE to: measure at least a line-of-sight (LOS) path and anon-line-of-sight (NLOS) path of a first downlink positioning referencesignal (DL-PRS) from a first transmission-reception point (TRP); measureat least an LOS path and an NLOS path of a second DL-PRS from a secondTRP; measure at least an LOS path and an NLOS path of a third DL-PRSfrom a third TRP; and enable a location of a non-participating targetobject to be determined based, at least in part, on a first referencesignal time difference (RSTD) between a time of arrival (ToA) of the LOSpath of the first DL-PRS and a ToA of the NLOS path of the first DL-PRS,a second RSTD between the ToA of the LOS path of the first DL-PRS and aToA of the NLOS path of the second DL-PRS, and a third RSTD between theToA of the LOS path of the first DL-PRS and a ToA of the NLOS path ofthe third DL-PRS, wherein the non-participating target object does notparticipate in determining the location of the non-participating targetobject.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates an example wireless communications system, accordingto aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures,according to aspects of the disclosure.

FIGS. 3A, 3B, and 3C are simplified block diagrams of several sampleaspects of components that may be employed in a user equipment (UE), abase station, and a network entity, respectively, and configured tosupport communications as taught herein.

FIG. 4 is a diagram illustrating an example frame structure, accordingto aspects of the disclosure.

FIG. 5 is a graph showing a radio frequency (RF) channel impulseresponse over time, according to aspects of the disclosure.

FIG. 6 illustrates a time difference of arrival (TDOA)-based positioningprocedure in an example wireless communications system, according toaspects of the disclosure.

FIG. 7 is a diagram illustrating example measurement timings of aTDOA-based positioning procedure, according to aspects of thedisclosure.

FIG. 8 is a diagram illustrating example hyperbolas that satisfy variousTDOA-based equations, according to aspects of the disclosure.

FIGS. 9A and 9B illustrate a comparison between a conventionalpositioning procedure scenario that only locates a UE and a scenario inwhich both a UE and a device-free object can be located.

FIG. 10 illustrates measurements performed by a UE to enable thedetection of a device-free object, according to aspects of thedisclosure.

FIG. 11 is a diagram of an example network in which three base stationstransmit RF signals to a UE that are reflected off a device-free object,according to aspects of the disclosure.

FIG. 12 is a diagram of an example network of three base stations, a UE,and a device-free object, according to aspects of the disclosure.

FIG. 13 is a diagram of an example network of three base stations, a UE,and a device-free object, according to aspects of the disclosure.

FIG. 14 illustrates an example method of wireless sensing, according toaspects of the disclosure.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description andrelated drawings directed to various examples provided for illustrationpurposes. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Those of skill in the art will appreciate that the information andsignals described below may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the description below may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof, depending inpart on the particular application, in part on the desired design, inpart on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

As used herein, the terms “user equipment” (UE) and “base station” arenot intended to be specific or otherwise limited to any particular radioaccess technology (RAT), unless otherwise noted. In general, a UE may beany wireless communication device (e.g., a mobile phone, router, tabletcomputer, laptop computer, consumer asset locating device, wearable(e.g., smartwatch, glasses, augmented reality (AR)/virtual reality (VR)headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.),Internet of Things (IoT) device, etc.) used by a user to communicateover a wireless communications network. A UE may be mobile or may (e.g.,at certain times) be stationary, and may communicate with a radio accessnetwork (RAN). As used herein, the term “UE” may be referred tointerchangeably as an “access terminal” or “AT,” a “client device,” a“wireless device,” a “subscriber device,” a “subscriber terminal,” a“subscriber station,” a “user terminal” or “UT,” a “mobile device,” a“mobile terminal,” a “mobile station,” or variations thereof. Generally,UEs can communicate with a core network via a RAN, and through the corenetwork the UEs can be connected with external networks such as theInternet and with other UEs. Of course, other mechanisms of connectingto the core network and/or the Internet are also possible for the UEs,such as over wired access networks, wireless local area network (WLAN)networks (e.g., based on the Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 specification, etc.) and so on.

A base station may operate according to one of several RATs incommunication with UEs depending on the network in which it is deployed,and may be alternatively referred to as an access point (AP), a networknode, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), aNew Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A basestation may be used primarily to support wireless access by UEs,including supporting data, voice, and/or signaling connections for thesupported UEs. In some systems a base station may provide purely edgenode signaling functions while in other systems it may provideadditional control and/or network management functions. A communicationlink through which UEs can send signals to a base station is called anuplink (UL) channel (e.g., a reverse traffic channel, a reverse controlchannel, an access channel, etc.). A communication link through whichthe base station can send signals to UEs is called a downlink (DL) orforward link channel (e.g., a paging channel, a control channel, abroadcast channel, a forward traffic channel, etc.). As used herein theterm traffic channel (TCH) can refer to either an uplink/reverse ordownlink/forward traffic channel.

The term “base station” may refer to a single physicaltransmission-reception point (TRP) or to multiple physical TRPs that mayor may not be co-located. For example, where the term “base station”refers to a single physical TRP, the physical TRP may be an antenna ofthe base station corresponding to a cell (or several cell sectors) ofthe base station. Where the term “base station” refers to multipleco-located physical TRPs, the physical TRPs may be an array of antennas(e.g., as in a multiple-input multiple-output (MIMO) system or where thebase station employs beamforming) of the base station. Where the term“base station” refers to multiple non-co-located physical TRPs, thephysical TRPs may be a distributed antenna system (DAS) (a network ofspatially separated antennas connected to a common source via atransport medium) or a remote radio head (RRH) (a remote base stationconnected to a serving base station). Alternatively, the non-co-locatedphysical TRPs may be the serving base station receiving the measurementreport from the UE and a neighbor base station whose reference radiofrequency (RF) signals the UE is measuring. Because a TRP is the pointfrom which a base station transmits and receives wireless signals, asused herein, references to transmission from or reception at a basestation are to be understood as referring to a particular TRP of thebase station.

In some implementations that support positioning of UEs, a base stationmay not support wireless access by UEs (e.g., may not support data,voice, and/or signaling connections for UEs), but may instead transmitreference signals to UEs to be measured by the UEs, and/or may receiveand measure signals transmitted by the UEs. Such a base station may bereferred to as a positioning beacon (e.g., when transmitting signals toUEs) and/or as a location measurement unit (e.g., when receiving andmeasuring signals from UEs).

An “RF signal” comprises an electromagnetic wave of a given frequencythat transports information through the space between a transmitter anda receiver. As used herein, a transmitter may transmit a single “RFsignal” or multiple “RF signals” to a receiver. However, the receivermay receive multiple “RF signals” corresponding to each transmitted RFsignal due to the propagation characteristics of RF signals throughmultipath channels. The same transmitted RF signal on different pathsbetween the transmitter and receiver may be referred to as a “multipath”RF signal. As used herein, an RF signal may also be referred to as a“wireless signal” or simply a “signal” where it is clear from thecontext that the term “signal” refers to a wireless signal or an RFsignal.

FIG. 1 illustrates an example wireless communications system 100,according to aspects of the disclosure. The wireless communicationssystem 100 (which may also be referred to as a wireless wide areanetwork (WWAN)) may include various base stations 102 (labeled “BS”) andvarious UEs 104. The base stations 102 may include macro cell basestations (high power cellular base stations) and/or small cell basestations (low power cellular base stations). In an aspect, the macrocell base stations may include eNBs and/or ng-eNBs where the wirelesscommunications system 100 corresponds to an LTE network, or gNBs wherethe wireless communications system 100 corresponds to a NR network, or acombination of both, and the small cell base stations may includefemtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC))through backhaul links 122, and through the core network 170 to one ormore location servers 172 (e.g., a location management function (LMF) ora secure user plane location (SUPL) location platform (SLP)). Thelocation server(s) 172 may be part of core network 170 or may beexternal to core network 170. In addition to other functions, the basestations 102 may perform functions that relate to one or more oftransferring user data, radio channel ciphering and deciphering,integrity protection, header compression, mobility control functions(e.g., handover, dual connectivity), inter-cell interferencecoordination, connection setup and release, load balancing, distributionfor non-access stratum (NAS) messages, NAS node selection,synchronization, RAN sharing, multimedia broadcast multicast service(MBMS), subscriber and equipment trace, RAN information management(RIM), paging, positioning, and delivery of warning messages. The basestations 102 may communicate with each other directly or indirectly(e.g., through the EPC/5GC) over backhaul links 134, which may be wiredor wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each geographic coverage area110. A “cell” is a logical communication entity used for communicationwith a base station (e.g., over some frequency resource, referred to asa carrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCI), an enhanced cell identifier (ECI), a virtual cell identifier(VCI), a cell global identifier (CGI), etc.) for distinguishing cellsoperating via the same or a different carrier frequency. In some cases,different cells may be configured according to different protocol types(e.g., machine-type communication (MTC), narrowband IoT (NB-IoT),enhanced mobile broadband (eMBB), or others) that may provide access fordifferent types of UEs. Because a cell is supported by a specific basestation, the term “cell” may refer to either or both of the logicalcommunication entity and the base station that supports it, depending onthe context. In addition, because a TRP is typically the physicaltransmission point of a cell, the terms “cell” and “TRP” may be usedinterchangeably. In some cases, the term “cell” may also refer to ageographic coverage area of a base station (e.g., a sector), insofar asa carrier frequency can be detected and used for communication withinsome portion of geographic coverage areas 110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell basestation 102′ (labeled “SC” for “small cell”) may have a geographiccoverage area 110′ that substantially overlaps with the geographiccoverage area 110 of one or more macro cell base stations 102. A networkthat includes both small cell and macro cell base stations may be knownas a heterogeneous network. A heterogeneous network may also includehome eNBs (HeNBs), which may provide service to a restricted group knownas a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs104 may include uplink (also referred to as reverse link) transmissionsfrom a UE 104 to a base station 102 and/or downlink (DL) (also referredto as forward link) transmissions from a base station 102 to a UE 104.The communication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to downlink anduplink (e.g., more or less carriers may be allocated for downlink thanfor uplink).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) or listen before talk (LBT) procedureprior to communicating in order to determine whether the channel isavailable.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or NRtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. NR in unlicensed spectrum maybe referred to as NR-U. LTE in an unlicensed spectrum may be referred toas LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a millimeterwave (mmW) base station 180 that may operate in mmW frequencies and/ornear mmW frequencies in communication with a UE 182. Extremely highfrequency (EHF) is part of the RF in the electromagnetic spectrum. EHFhas a range of 30 GHz to 300 GHz and a wavelength between 1 millimeterand 10 millimeters. Radio waves in this band may be referred to as amillimeter wave. Near mmW may extend down to a frequency of 3 GHz with awavelength of 100 millimeters. The super high frequency (SHF) bandextends between 3 GHz and 30 GHz, also referred to as centimeter wave.Communications using the mmW/near mmW radio frequency band have highpath loss and a relatively short range. The mmW base station 180 and theUE 182 may utilize beamforming (transmit and/or receive) over a mmWcommunication link 184 to compensate for the extremely high path lossand short range. Further, it will be appreciated that in alternativeconfigurations, one or more base stations 102 may also transmit usingmmW or near mmW and beamforming. Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

Transmit beams may be quasi-co-located, meaning that they appear to thereceiver (e.g., a UE) as having the same parameters, regardless ofwhether or not the transmitting antennas of the network node themselvesare physically co-located. In NR, there are four types ofquasi-co-location (QCL) relations. Specifically, a QCL relation of agiven type means that certain parameters about a second reference RFsignal on a second beam can be derived from information about a sourcereference RF signal on a source beam. Thus, if the source reference RFsignal is QCL Type A, the receiver can use the source reference RFsignal to estimate the Doppler shift, Doppler spread, average delay, anddelay spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type B, the receivercan use the source reference RF signal to estimate the Doppler shift andDoppler spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type C, the receivercan use the source reference RF signal to estimate the Doppler shift andaverage delay of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type D, the receivercan use the source reference RF signal to estimate the spatial receiveparameter of a second reference RF signal transmitted on the samechannel.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

Transmit and receive beams may be spatially related. A spatial relationmeans that parameters for a second beam (e.g., a transmit or receivebeam) for a second reference signal can be derived from informationabout a first beam (e.g., a receive beam or a transmit beam) for a firstreference signal. For example, a UE may use a particular receive beam toreceive a reference downlink reference signal (e.g., synchronizationsignal block (SSB)) from a base station. The UE can then form a transmitbeam for sending an uplink reference signal (e.g., sounding referencesignal (SRS)) to that base station based on the parameters of thereceive beam.

Note that a “downlink” beam may be either a transmit beam or a receivebeam, depending on the entity forming it. For example, if a base stationis forming the downlink beam to transmit a reference signal to a UE, thedownlink beam is a transmit beam. If the UE is forming the downlinkbeam, however, it is a receive beam to receive the downlink referencesignal. Similarly, an “uplink” beam may be either a transmit beam or areceive beam, depending on the entity forming it. For example, if a basestation is forming the uplink beam, it is an uplink receive beam, and ifa UE is forming the uplink beam, it is an uplink transmit beam.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102/180, UEs 104/182) operate is divided into multiplefrequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). mmWfrequency bands generally include the FR2, FR3, and FR4 frequencyranges. As such, the terms “mmW” and “FR2” or “FR3” or “FR4” maygenerally be used interchangeably.

In a multi-carrier system, such as 5G, one of the carrier frequencies isreferred to as the “primary carrier” or “anchor carrier” or “primaryserving cell” or “PCell,” and the remaining carrier frequencies arereferred to as “secondary carriers” or “secondary serving cells” or“SCells.” In carrier aggregation, the anchor carrier is the carrieroperating on the primary frequency (e.g., FR1) utilized by a UE 104/182and the cell in which the UE 104/182 either performs the initial radioresource control (RRC) connection establishment procedure or initiatesthe RRC connection re-establishment procedure. The primary carriercarries all common and UE-specific control channels, and may be acarrier in a licensed frequency (however, this is not always the case).A secondary carrier is a carrier operating on a second frequency (e.g.,FR2) that may be configured once the RRC connection is establishedbetween the UE 104 and the anchor carrier and that may be used toprovide additional radio resources. In some cases, the secondary carriermay be a carrier in an unlicensed frequency. The secondary carrier maycontain only necessary signaling information and signals, for example,those that are UE-specific may not be present in the secondary carrier,since both primary uplink and downlink carriers are typicallyUE-specific. This means that different UEs 104/182 in a cell may havedifferent downlink primary carriers. The same is true for the uplinkprimary carriers. The network is able to change the primary carrier ofany UE 104/182 at any time. This is done, for example, to balance theload on different carriers. Because a “serving cell” (whether a PCell oran SCell) corresponds to a carrier frequency/component carrier overwhich some base station is communicating, the term “cell,” “servingcell,” “component carrier,” “carrier frequency,” and the like can beused interchangeably.

For example, still referring to FIG. 1 , one of the frequencies utilizedby the macro cell base stations 102 may be an anchor carrier (or“PCell”) and other frequencies utilized by the macro cell base stations102 and/or the mmW base station 180 may be secondary carriers(“SCells”). The simultaneous transmission and/or reception of multiplecarriers enables the UE 104/182 to significantly increase its datatransmission and/or reception rates. For example, two 20 MHz aggregatedcarriers in a multi-carrier system would theoretically lead to atwo-fold increase in data rate (i.e., 40 MHz), compared to that attainedby a single 20 MHz carrier.

The wireless communications system 100 may further include a UE 164 thatmay communicate with a macro cell base station 102 over a communicationlink 120 and/or the mmW base station 180 over a mmW communication link184. For example, the macro cell base station 102 may support a PCelland one or more SCells for the UE 164 and the mmW base station 180 maysupport one or more SCells for the UE 164.

In the example of FIG. 1 , any of the illustrated UEs (shown in FIG. 1as a single UE 104 for simplicity) may receive signals 124 from one ormore Earth orbiting space vehicles (SVs) 112 (e.g., satellites). In anaspect, the SVs 112 may be part of a satellite positioning system that aUE 104 can use as an independent source of location information. Asatellite positioning system typically includes a system of transmitters(e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) todetermine their location on or above the Earth based, at least in part,on positioning signals (e.g., signals 124) received from thetransmitters. Such a transmitter typically transmits a signal markedwith a repeating pseudo-random noise (PN) code of a set number of chips.While typically located in SVs 112, transmitters may sometimes belocated on ground-based control stations, base stations 102, and/orother UEs 104. A UE 104 may include one or more dedicated receiversspecifically designed to receive signals 124 for deriving geo locationinformation from the SVs 112.

In a satellite positioning system, the use of signals 124 can beaugmented by various satellite-based augmentation systems (SBAS) thatmay be associated with or otherwise enabled for use with one or moreglobal and/or regional navigation satellite systems. For example an SBASmay include an augmentation system(s) that provides integrityinformation, differential corrections, etc., such as the Wide AreaAugmentation System (WAAS), the European Geostationary NavigationOverlay Service (EGNOS), the Multi-functional Satellite AugmentationSystem (MSAS), the Global Positioning System (GPS) Aided Geo AugmentedNavigation or GPS and Geo Augmented Navigation system (GAGAN), and/orthe like. Thus, as used herein, a satellite positioning system mayinclude any combination of one or more global and/or regional navigationsatellites associated with such one or more satellite positioningsystems.

In an aspect, SVs 112 may additionally or alternatively be part of oneor more non-terrestrial networks (NTNs). In an NTN, an SV 112 isconnected to an earth station (also referred to as a ground station, NTNgateway, or gateway), which in turn is connected to an element in a 5Gnetwork, such as a modified base station 102 (without a terrestrialantenna) or a network node in a 5GC. This element would in turn provideaccess to other elements in the 5G network and ultimately to entitiesexternal to the 5G network, such as Internet web servers and other userdevices. In that way, a UE 104 may receive communication signals (e.g.,signals 124) from an SV 112 instead of, or in addition to, communicationsignals from a terrestrial base station 102.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links (referred to as “sidelinks”). In the example ofFIG. 1 , UE 190 has a D2D P2P link 192 with one of the UEs 104 connectedto one of the base stations 102 (e.g., through which UE 190 mayindirectly obtain cellular connectivity) and a D2D P2P link 194 withWLAN STA 152 connected to the WLAN AP 150 (through which UE 190 mayindirectly obtain WLAN-based Internet connectivity). In an example, theD2D P2P links 192 and 194 may be supported with any well-known D2D RAT,such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

FIG. 2A illustrates an example wireless network structure 200. Forexample, a 5GC 210 (also referred to as a Next Generation Core (NGC))can be viewed functionally as control plane (C-plane) functions 214(e.g., UE registration, authentication, network access, gatewayselection, etc.) and user plane (U-plane) functions 212, (e.g., UEgateway function, access to data networks, IP routing, etc.) whichoperate cooperatively to form the core network. User plane interface(NG-U) 213 and control plane interface (NG-C) 215 connect the gNB 222 tothe 5GC 210 and specifically to the user plane functions 212 and controlplane functions 214, respectively. In an additional configuration, anng-eNB 224 may also be connected to the 5GC 210 via NG-C 215 to thecontrol plane functions 214 and NG-U 213 to user plane functions 212.Further, ng-eNB 224 may directly communicate with gNB 222 via a backhaulconnection 223. In some configurations, a Next Generation RAN (NG-RAN)220 may have one or more gNBs 222, while other configurations includeone or more of both ng-eNBs 224 and gNBs 222. Either (or both) gNB 222or ng-eNB 224 may communicate with one or more UEs 204 (e.g., any of theUEs described herein).

Another optional aspect may include a location server 230, which may bein communication with the 5GC 210 to provide location assistance forUE(s) 204. The location server 230 can be implemented as a plurality ofseparate servers (e.g., physically separate servers, different softwaremodules on a single server, different software modules spread acrossmultiple physical servers, etc.), or alternately may each correspond toa single server. The location server 230 can be configured to supportone or more location services for UEs 204 that can connect to thelocation server 230 via the core network, 5GC 210, and/or via theInternet (not illustrated). Further, the location server 230 may beintegrated into a component of the core network, or alternatively may beexternal to the core network (e.g., a third party server, such as anoriginal equipment manufacturer (OEM) server or service server).

FIG. 2B illustrates another example wireless network structure 250. A5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewedfunctionally as control plane functions, provided by an access andmobility management function (AMF) 264, and user plane functions,provided by a user plane function (UPF) 262, which operate cooperativelyto form the core network (i.e., 5GC 260). The functions of the AMF 264include registration management, connection management, reachabilitymanagement, mobility management, lawful interception, transport forsession management (SM) messages between one or more UEs 204 (e.g., anyof the UEs described herein) and a session management function (SMF)266, transparent proxy services for routing SM messages, accessauthentication and access authorization, transport for short messageservice (SMS) messages between the UE 204 and the short message servicefunction (SMSF) (not shown), and security anchor functionality (SEAF).The AMF 264 also interacts with an authentication server function (AUSF)(not shown) and the UE 204, and receives the intermediate key that wasestablished as a result of the UE 204 authentication process. In thecase of authentication based on a UMTS (universal mobiletelecommunications system) subscriber identity module (USIM), the AMF264 retrieves the security material from the AUSF. The functions of theAMF 264 also include security context management (SCM). The SCM receivesa key from the SEAF that it uses to derive access-network specific keys.The functionality of the AMF 264 also includes location servicesmanagement for regulatory services, transport for location servicesmessages between the UE 204 and a location management function (LMF) 270(which acts as a location server 230), transport for location servicesmessages between the NG-RAN 220 and the LMF 270, evolved packet system(EPS) bearer identifier allocation for interworking with the EPS, and UE204 mobility event notification. In addition, the AMF 264 also supportsfunctionalities for non-3GPP (Third Generation Partnership Project)access networks.

Functions of the UPF 262 include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to a data network(not shown), providing packet routing and forwarding, packet inspection,user plane policy rule enforcement (e.g., gating, redirection, trafficsteering), lawful interception (user plane collection), traffic usagereporting, quality of service (QoS) handling for the user plane (e.g.,uplink/downlink rate enforcement, reflective QoS marking in thedownlink), uplink traffic verification (service data flow (SDF) to QoSflow mapping), transport level packet marking in the uplink anddownlink, downlink packet buffering and downlink data notificationtriggering, and sending and forwarding of one or more “end markers” tothe source RAN node. The UPF 262 may also support transfer of locationservices messages over a user plane between the UE 204 and a locationserver, such as an SLP 272.

The functions of the SMF 266 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF262 to route traffic to the proper destination, control of part ofpolicy enforcement and QoS, and downlink data notification. Theinterface over which the SMF 266 communicates with the AMF 264 isreferred to as the N11 interface.

Another optional aspect may include an LMF 270, which may be incommunication with the 5GC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, 5GC 260, and/or via the Internet (not illustrated). The SLP 272may support similar functions to the LMF 270, but whereas the LMF 270may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a controlplane (e.g., using interfaces and protocols intended to convey signalingmessages and not voice or data), the SLP 272 may communicate with UEs204 and external clients (not shown in FIG. 2B) over a user plane (e.g.,using protocols intended to carry voice and/or data like thetransmission control protocol (TCP) and/or IP).

User plane interface 263 and control plane interface 265 connect the 5GC260, and specifically the UPF 262 and AMF 264, respectively, to one ormore gNBs 222 and/or ng-eNBs 224 in the NG-RAN 220. The interfacebetween gNB(s) 222 and/or ng-eNB(s) 224 and the AMF 264 is referred toas the “N2” interface, and the interface between gNB(s) 222 and/orng-eNB(s) 224 and the UPF 262 is referred to as the “N3” interface. ThegNB(s) 222 and/or ng-eNB(s) 224 of the NG-RAN 220 may communicatedirectly with each other via backhaul connections 223, referred to asthe “Xn-C” interface. One or more of gNBs 222 and/or ng-eNBs 224 maycommunicate with one or more UEs 204 over a wireless interface, referredto as the “Uu” interface.

The functionality of a gNB 222 is divided between a gNB central unit(gNB-CU) 226 and one or more gNB distributed units (gNB-DUs) 228. Theinterface 232 between the gNB-CU 226 and the one or more gNB-DUs 228 isreferred to as the “F1” interface. A gNB-CU 226 is a logical node thatincludes the base station functions of transferring user data, mobilitycontrol, radio access network sharing, positioning, session management,and the like, except for those functions allocated exclusively to thegNB-DU(s) 228. More specifically, the gNB-CU 226 hosts the radioresource control (RRC), service data adaptation protocol (SDAP), andpacket data convergence protocol (PDCP) protocols of the gNB 222. AgNB-DU 228 is a logical node that hosts the radio link control (RLC),medium access control (MAC), and physical (PHY) layers of the gNB 222.Its operation is controlled by the gNB-CU 226. One gNB-DU 228 cansupport one or more cells, and one cell is supported by only one gNB-DU228. Thus, a UE 204 communicates with the gNB-CU 226 via the RRC, SDAP,and PDCP layers and with a gNB-DU 228 via the RLC, MAC, and PHY layers.

FIGS. 3A, 3B, and 3C illustrate several example components (representedby corresponding blocks) that may be incorporated into a UE 302 (whichmay correspond to any of the UEs described herein), a base station 304(which may correspond to any of the base stations described herein), anda network entity 306 (which may correspond to or embody any of thenetwork functions described herein, including the location server 230and the LMF 270, or alternatively may be independent from the NG-RAN 220and/or 5GC 210/260 infrastructure depicted in FIGS. 2A and 2B, such as aprivate network) to support the file transmission operations as taughtherein. It will be appreciated that these components may be implementedin different types of apparatuses in different implementations (e.g., inan ASIC, in a system-on-chip (SoC), etc.). The illustrated componentsmay also be incorporated into other apparatuses in a communicationsystem. For example, other apparatuses in a system may includecomponents similar to those described to provide similar functionality.Also, a given apparatus may contain one or more of the components. Forexample, an apparatus may include multiple transceiver components thatenable the apparatus to operate on multiple carriers and/or communicatevia different technologies.

The UE 302 and the base station 304 each include one or more wirelesswide area network (WWAN) transceivers 310 and 350, respectively,providing means for communicating (e.g., means for transmitting, meansfor receiving, means for measuring, means for tuning, means forrefraining from transmitting, etc.) via one or more wirelesscommunication networks (not shown), such as an NR network, an LTEnetwork, a GSM network, and/or the like. The WWAN transceivers 310 and350 may each be connected to one or more antennas 316 and 356,respectively, for communicating with other network nodes, such as otherUEs, access points, base stations (e.g., eNBs, gNBs), etc., via at leastone designated RAT (e.g., NR, LTE, GSM, etc.) over a wirelesscommunication medium of interest (e.g., some set of time/frequencyresources in a particular frequency spectrum). The WWAN transceivers 310and 350 may be variously configured for transmitting and encodingsignals 318 and 358 (e.g., messages, indications, information, and soon), respectively, and, conversely, for receiving and decoding signals318 and 358 (e.g., messages, indications, information, pilots, and soon), respectively, in accordance with the designated RAT. Specifically,the WWAN transceivers 310 and 350 include one or more transmitters 314and 354, respectively, for transmitting and encoding signals 318 and358, respectively, and one or more receivers 312 and 352, respectively,for receiving and decoding signals 318 and 358, respectively.

The UE 302 and the base station 304 each also include, at least in somecases, one or more short-range wireless transceivers 320 and 360,respectively. The short-range wireless transceivers 320 and 360 may beconnected to one or more antennas 326 and 366, respectively, and providemeans for communicating (e.g., means for transmitting, means forreceiving, means for measuring, means for tuning, means for refrainingfrom transmitting, etc.) with other network nodes, such as other UEs,access points, base stations, etc., via at least one designated RAT(e.g., WiFi, LTE-D, Bluetooth®, Zigbee®, Z-Wave®, PC5, dedicatedshort-range communications (DSRC), wireless access for vehicularenvironments (WAVE), near-field communication (NFC), etc.) over awireless communication medium of interest. The short-range wirelesstransceivers 320 and 360 may be variously configured for transmittingand encoding signals 328 and 368 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 328 and 368 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the short-range wireless transceivers 320and 360 include one or more transmitters 324 and 364, respectively, fortransmitting and encoding signals 328 and 368, respectively, and one ormore receivers 322 and 362, respectively, for receiving and decodingsignals 328 and 368, respectively. As specific examples, the short-rangewireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth®transceivers, Zigbee® and/or Z-Wave® transceivers, NFC transceivers, orvehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X)transceivers.

The UE 302 and the base station 304 also include, at least in somecases, satellite signal receivers 330 and 370. The satellite signalreceivers 330 and 370 may be connected to one or more antennas 336 and376, respectively, and may provide means for receiving and/or measuringsatellite positioning/communication signals 338 and 378, respectively.Where the satellite signal receivers 330 and 370 are satellitepositioning system receivers, the satellite positioning/communicationsignals 338 and 378 may be global positioning system (GPS) signals,global navigation satellite system (GLONASS) signals, Galileo signals,Beidou signals, Indian Regional Navigation Satellite System (NAVIC),Quasi-Zenith Satellite System (QZSS), etc. Where the satellite signalreceivers 330 and 370 are non-terrestrial network (NTN) receivers, thesatellite positioning/communication signals 338 and 378 may becommunication signals (e.g., carrying control and/or user data)originating from a 5G network. The satellite signal receivers 330 and370 may comprise any suitable hardware and/or software for receiving andprocessing satellite positioning/communication signals 338 and 378,respectively. The satellite signal receivers 330 and 370 may requestinformation and operations as appropriate from the other systems, and,at least in some cases, perform calculations to determine locations ofthe UE 302 and the base station 304, respectively, using measurementsobtained by any suitable satellite positioning system algorithm.

The base station 304 and the network entity 306 each include one or morenetwork transceivers 380 and 390, respectively, providing means forcommunicating (e.g., means for transmitting, means for receiving, etc.)with other network entities (e.g., other base stations 304, othernetwork entities 306). For example, the base station 304 may employ theone or more network transceivers 380 to communicate with other basestations 304 or network entities 306 over one or more wired or wirelessbackhaul links. As another example, the network entity 306 may employthe one or more network transceivers 390 to communicate with one or morebase station 304 over one or more wired or wireless backhaul links, orwith other network entities 306 over one or more wired or wireless corenetwork interfaces.

A transceiver may be configured to communicate over a wired or wirelesslink. A transceiver (whether a wired transceiver or a wirelesstransceiver) includes transmitter circuitry (e.g., transmitters 314,324, 354, 364) and receiver circuitry (e.g., receivers 312, 322, 352,362). A transceiver may be an integrated device (e.g., embodyingtransmitter circuitry and receiver circuitry in a single device) in someimplementations, may comprise separate transmitter circuitry andseparate receiver circuitry in some implementations, or may be embodiedin other ways in other implementations. The transmitter circuitry andreceiver circuitry of a wired transceiver (e.g., network transceivers380 and 390 in some implementations) may be coupled to one or more wirednetwork interface ports. Wireless transmitter circuitry (e.g.,transmitters 314, 324, 354, 364) may include or be coupled to aplurality of antennas (e.g., antennas 316, 326, 356, 366), such as anantenna array, that permits the respective apparatus (e.g., UE 302, basestation 304) to perform transmit “beamforming,” as described herein.Similarly, wireless receiver circuitry (e.g., receivers 312, 322, 352,362) may include or be coupled to a plurality of antennas (e.g.,antennas 316, 326, 356, 366), such as an antenna array, that permits therespective apparatus (e.g., UE 302, base station 304) to perform receivebeamforming, as described herein. In an aspect, the transmittercircuitry and receiver circuitry may share the same plurality ofantennas (e.g., antennas 316, 326, 356, 366), such that the respectiveapparatus can only receive or transmit at a given time, not both at thesame time. A wireless transceiver (e.g., WWAN transceivers 310 and 350,short-range wireless transceivers 320 and 360) may also include anetwork listen module (NLM) or the like for performing variousmeasurements.

As used herein, the various wireless transceivers (e.g., transceivers310, 320, 350, and 360, and network transceivers 380 and 390 in someimplementations) and wired transceivers (e.g., network transceivers 380and 390 in some implementations) may generally be characterized as “atransceiver,” “at least one transceiver,” or “one or more transceivers.”As such, whether a particular transceiver is a wired or wirelesstransceiver may be inferred from the type of communication performed.For example, backhaul communication between network devices or serverswill generally relate to signaling via a wired transceiver, whereaswireless communication between a UE (e.g., UE 302) and a base station(e.g., base station 304) will generally relate to signaling via awireless transceiver.

The UE 302, the base station 304, and the network entity 306 alsoinclude other components that may be used in conjunction with theoperations as disclosed herein. The UE 302, the base station 304, andthe network entity 306 include one or more processors 332, 384, and 394,respectively, for providing functionality relating to, for example,wireless communication, and for providing other processingfunctionality. The processors 332, 384, and 394 may therefore providemeans for processing, such as means for determining, means forcalculating, means for receiving, means for transmitting, means forindicating, etc. In an aspect, the processors 332, 384, and 394 mayinclude, for example, one or more general purpose processors, multi-coreprocessors, central processing units (CPUs), ASICs, digital signalprocessors (DSPs), field programmable gate arrays (FPGAs), otherprogrammable logic devices or processing circuitry, or variouscombinations thereof.

The UE 302, the base station 304, and the network entity 306 includememory circuitry implementing memories 340, 386, and 396 (e.g., eachincluding a memory device), respectively, for maintaining information(e.g., information indicative of reserved resources, thresholds,parameters, and so on). The memories 340, 386, and 396 may thereforeprovide means for storing, means for retrieving, means for maintaining,etc. In some cases, the UE 302, the base station 304, and the networkentity 306 may include sensing component 342, 388, and 398,respectively. The sensing component 342, 388, and 398 may be hardwarecircuits that are part of or coupled to the processors 332, 384, and394, respectively, that, when executed, cause the UE 302, the basestation 304, and the network entity 306 to perform the functionalitydescribed herein. In other aspects, the sensing component 342, 388, and398 may be external to the processors 332, 384, and 394 (e.g., part of amodem processing system, integrated with another processing system,etc.). Alternatively, the sensing component 342, 388, and 398 may bememory modules stored in the memories 340, 386, and 396, respectively,that, when executed by the processors 332, 384, and 394 (or a modemprocessing system, another processing system, etc.), cause the UE 302,the base station 304, and the network entity 306 to perform thefunctionality described herein. FIG. 3A illustrates possible locationsof the sensing component 342, which may be, for example, part of the oneor more WWAN transceivers 310, the memory 340, the one or moreprocessors 332, or any combination thereof, or may be a standalonecomponent. FIG. 3B illustrates possible locations of the sensingcomponent 388, which may be, for example, part of the one or more WWANtransceivers 350, the memory 386, the one or more processors 384, or anycombination thereof, or may be a standalone component. FIG. 3Cillustrates possible locations of the sensing component 398, which maybe, for example, part of the one or more network transceivers 390, thememory 396, the one or more processors 394, or any combination thereof,or may be a standalone component.

The UE 302 may include one or more sensors 344 coupled to the one ormore processors 332 to provide means for sensing or detecting movementand/or orientation information that is independent of motion dataderived from signals received by the one or more WWAN transceivers 310,the one or more short-range wireless transceivers 320, and/or thesatellite signal receiver 330. By way of example, the sensor(s) 344 mayinclude an accelerometer (e.g., a micro-electrical mechanical systems(MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), analtimeter (e.g., a barometric pressure altimeter), and/or any other typeof movement detection sensor. Moreover, the sensor(s) 344 may include aplurality of different types of devices and combine their outputs inorder to provide motion information. For example, the sensor(s) 344 mayuse a combination of a multi-axis accelerometer and orientation sensorsto provide the ability to compute positions in two-dimensional (2D)and/or three-dimensional (3D) coordinate systems.

In addition, the UE 302 includes a user interface 346 providing meansfor providing indications (e.g., audible and/or visual indications) to auser and/or for receiving user input (e.g., upon user actuation of asensing device such a keypad, a touch screen, a microphone, and so on).Although not shown, the base station 304 and the network entity 306 mayalso include user interfaces.

Referring to the one or more processors 384 in more detail, in thedownlink, IP packets from the network entity 306 may be provided to theprocessor 384. The one or more processors 384 may implementfunctionality for an RRC layer, a packet data convergence protocol(PDCP) layer, a radio link control (RLC) layer, and a medium accesscontrol (MAC) layer. The one or more processors 384 may provide RRClayer functionality associated with broadcasting of system information(e.g., master information block (MIB), system information blocks(SIBs)), RRC connection control (e.g., RRC connection paging, RRCconnection establishment, RRC connection modification, and RRCconnection release), inter-RAT mobility, and measurement configurationfor UE measurement reporting; PDCP layer functionality associated withheader compression/decompression, security (ciphering, deciphering,integrity protection, integrity verification), and handover supportfunctions; RLC layer functionality associated with the transfer of upperlayer PDUs, error correction through automatic repeat request (ARQ),concatenation, segmentation, and reassembly of RLC service data units(SDUs), re-segmentation of RLC data PDUs, and reordering of RLC dataPDUs; and MAC layer functionality associated with mapping betweenlogical channels and transport channels, scheduling informationreporting, error correction, priority handling, and logical channelprioritization.

The transmitter 354 and the receiver 352 may implement Layer-1 (L1)functionality associated with various signal processing functions.Layer-1, which includes a physical (PHY) layer, may include errordetection on the transport channels, forward error correction (FEC)coding/decoding of the transport channels, interleaving, rate matching,mapping onto physical channels, modulation/demodulation of physicalchannels, and MIMO antenna processing. The transmitter 354 handlesmapping to signal constellations based on various modulation schemes(e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an orthogonalfrequency division multiplexing (OFDM) subcarrier, multiplexed with areference signal (e.g., pilot) in the time and/or frequency domain, andthen combined together using an inverse fast Fourier transform (IFFT) toproduce a physical channel carrying a time domain OFDM symbol stream.The OFDM symbol stream is spatially precoded to produce multiple spatialstreams. Channel estimates from a channel estimator may be used todetermine the coding and modulation scheme, as well as for spatialprocessing. The channel estimate may be derived from a reference signaland/or channel condition feedback transmitted by the UE 302. Eachspatial stream may then be provided to one or more different antennas356. The transmitter 354 may modulate an RF carrier with a respectivespatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respectiveantenna(s) 316. The receiver 312 recovers information modulated onto anRF carrier and provides the information to the one or more processors332. The transmitter 314 and the receiver 312 implement Layer-1functionality associated with various signal processing functions. Thereceiver 312 may perform spatial processing on the information torecover any spatial streams destined for the UE 302. If multiple spatialstreams are destined for the UE 302, they may be combined by thereceiver 312 into a single OFDM symbol stream. The receiver 312 thenconverts the OFDM symbol stream from the time-domain to the frequencydomain using a fast Fourier transform (FFT). The frequency domain signalcomprises a separate OFDM symbol stream for each subcarrier of the OFDMsignal. The symbols on each subcarrier, and the reference signal, arerecovered and demodulated by determining the most likely signalconstellation points transmitted by the base station 304. These softdecisions may be based on channel estimates computed by a channelestimator. The soft decisions are then decoded and de-interleaved torecover the data and control signals that were originally transmitted bythe base station 304 on the physical channel. The data and controlsignals are then provided to the one or more processors 332, whichimplements Layer-3 (L3) and Layer-2 (L2) functionality.

In the uplink, the one or more processors 332 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, and control signal processing to recover IPpackets from the core network. The one or more processors 332 are alsoresponsible for error detection.

Similar to the functionality described in connection with the downlinktransmission by the base station 304, the one or more processors 332provides RRC layer functionality associated with system information(e.g., MIB, SIBs) acquisition, RRC connections, and measurementreporting; PDCP layer functionality associated with headercompression/decompression, and security (ciphering, deciphering,integrity protection, integrity verification); RLC layer functionalityassociated with the transfer of upper layer PDUs, error correctionthrough ARQ, concatenation, segmentation, and reassembly of RLC SDUs,re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, multiplexing of MAC SDUs onto transport blocks(TBs), demultiplexing of MAC SDUs from TBs, scheduling informationreporting, error correction through hybrid automatic repeat request(HARM), priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator from a referencesignal or feedback transmitted by the base station 304 may be used bythe transmitter 314 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the transmitter 314 may be provided to different antenna(s)316. The transmitter 314 may modulate an RF carrier with a respectivespatial stream for transmission.

The uplink transmission is processed at the base station 304 in a mannersimilar to that described in connection with the receiver function atthe UE 302. The receiver 352 receives a signal through its respectiveantenna(s) 356. The receiver 352 recovers information modulated onto anRF carrier and provides the information to the one or more processors384.

In the uplink, the one or more processors 384 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, control signal processing to recover IP packetsfrom the UE 302. IP packets from the one or more processors 384 may beprovided to the core network. The one or more processors 384 are alsoresponsible for error detection.

For convenience, the UE 302, the base station 304, and/or the networkentity 306 are shown in FIGS. 3A, 3B, and 3C as including variouscomponents that may be configured according to the various examplesdescribed herein. It will be appreciated, however, that the illustratedcomponents may have different functionality in different designs. Inparticular, various components in FIGS. 3A to 3C are optional inalternative configurations and the various aspects includeconfigurations that may vary due to design choice, costs, use of thedevice, or other considerations. For example, in case of FIG. 3A, aparticular implementation of UE 302 may omit the WWAN transceiver(s) 310(e.g., a wearable device or tablet computer or PC or laptop may haveWi-Fi and/or Bluetooth capability without cellular capability), or mayomit the short-range wireless transceiver(s) 320 (e.g., cellular-only,etc.), or may omit the satellite signal receiver 330, or may omit thesensor(s) 344, and so on. In another example, in case of FIG. 3B, aparticular implementation of the base station 304 may omit the WWANtransceiver(s) 350 (e.g., a Wi-Fi “hotspot” access point withoutcellular capability), or may omit the short-range wirelesstransceiver(s) 360 (e.g., cellular-only, etc.), or may omit thesatellite receiver 370, and so on. For brevity, illustration of thevarious alternative configurations is not provided herein, but would bereadily understandable to one skilled in the art.

The various components of the UE 302, the base station 304, and thenetwork entity 306 may be communicatively coupled to each other overdata buses 334, 382, and 392, respectively. In an aspect, the data buses334, 382, and 392 may form, or be part of, a communication interface ofthe UE 302, the base station 304, and the network entity 306,respectively. For example, where different logical entities are embodiedin the same device (e.g., gNB and location server functionalityincorporated into the same base station 304), the data buses 334, 382,and 392 may provide communication between them.

The components of FIGS. 3A, 3B, and 3C may be implemented in variousways. In some implementations, the components of FIGS. 3A, 3B, and 3Cmay be implemented in one or more circuits such as, for example, one ormore processors and/or one or more ASICs (which may include one or moreprocessors). Here, each circuit may use and/or incorporate at least onememory component for storing information or executable code used by thecircuit to provide this functionality. For example, some or all of thefunctionality represented by blocks 310 to 346 may be implemented byprocessor and memory component(s) of the UE 302 (e.g., by execution ofappropriate code and/or by appropriate configuration of processorcomponents). Similarly, some or all of the functionality represented byblocks 350 to 388 may be implemented by processor and memorycomponent(s) of the base station 304 (e.g., by execution of appropriatecode and/or by appropriate configuration of processor components). Also,some or all of the functionality represented by blocks 390 to 398 may beimplemented by processor and memory component(s) of the network entity306 (e.g., by execution of appropriate code and/or by appropriateconfiguration of processor components). For simplicity, variousoperations, acts, and/or functions are described herein as beingperformed “by a UE,” “by a base station,” “by a network entity,” etc.However, as will be appreciated, such operations, acts, and/or functionsmay actually be performed by specific components or combinations ofcomponents of the UE 302, base station 304, network entity 306, etc.,such as the processors 332, 384, 394, the transceivers 310, 320, 350,and 360, the memories 340, 386, and 396, the sensing component 342, 388,and 398, etc.

In some designs, the network entity 306 may be implemented as a corenetwork component. In other designs, the network entity 306 may bedistinct from a network operator or operation of the cellular networkinfrastructure (e.g., NG RAN 220 and/or 5GC 210/260). For example, thenetwork entity 306 may be a component of a private network that may beconfigured to communicate with the UE 302 via the base station 304 orindependently from the base station 304 (e.g., over a non-cellularcommunication link, such as WiFi).

Various frame structures may be used to support downlink and uplinktransmissions between network nodes (e.g., base stations and UEs). FIG.4 is a diagram 400 illustrating an example frame structure, according toaspects of the disclosure. Other wireless communications technologiesmay have different frame structures and/or different channels.

LTE, and in some cases NR, utilizes OFDM on the downlink andsingle-carrier frequency division multiplexing (SC-FDM) on the uplink.Unlike LTE, however, NR has an option to use OFDM on the uplink as well.OFDM and SC-FDM partition the system bandwidth into multiple (K)orthogonal subcarriers, which are also commonly referred to as tones,bins, etc. Each subcarrier may be modulated with data. In general,modulation symbols are sent in the frequency domain with OFDM and in thetime domain with SC-FDM. The spacing between adjacent subcarriers may befixed, and the total number of subcarriers (K) may be dependent on thesystem bandwidth. For example, the spacing of the subcarriers may be 15kilohertz (kHz) and the minimum resource allocation (resource block) maybe 12 subcarriers (or 180 kHz). Consequently, the nominal FFT size maybe equal to 128, 256, 512, 1024, or 2048 for system bandwidth of 1.25,2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidthmay also be partitioned into subbands. For example, a subband may cover1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16subbands for system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz,respectively.

LTE supports a single numerology (subcarrier spacing (SCS), symbollength, etc.). In contrast, NR may support multiple numerologies (μ),for example, subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz(μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or greater may be available. Ineach subcarrier spacing, there are 14 symbols per slot. For 15 kHz SCS(μ=0), there is one slot per subframe, 10 slots per frame, the slotduration is 1 millisecond (ms), the symbol duration is 66.7 microseconds(μs), and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 50. For 30 kHz SCS (μ=1), there are two slots per subframe, 20slots per frame, the slot duration is 0.5 ms, the symbol duration is33.3 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 100. For 60 kHz SCS (μ=2), there are four slots per subframe, 40slots per frame, the slot duration is 0.25 ms, the symbol duration is16.7 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFTsize is 200. For 120 kHz SCS (μ=3), there are eight slots per subframe,80 slots per frame, the slot duration is 0.125 ms, the symbol durationis 8.33 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 400. For 240 kHz SCS (μ=4), there are 16 slots per subframe,160 slots per frame, the slot duration is 0.0625 ms, the symbol durationis 4.17 μs, and the maximum nominal system bandwidth (in MHz) with a 4KFFT size is 800.

In the example of FIG. 4 , a numerology of 15 kHz is used. Thus, in thetime domain, a 10 ms frame is divided into 10 equally sized subframes of1 ms each, and each subframe includes one time slot. In FIG. 4 , time isrepresented horizontally (on the X axis) with time increasing from leftto right, while frequency is represented vertically (on the Y axis) withfrequency increasing (or decreasing) from bottom to top.

A resource grid may be used to represent time slots, each time slotincluding one or more time-concurrent resource blocks (RBs) (alsoreferred to as physical RBs (PRBs)) in the frequency domain. Theresource grid is further divided into multiple resource elements (REs).An RE may correspond to one symbol length in the time domain and onesubcarrier in the frequency domain. In the numerology of FIG. 4 , for anormal cyclic prefix, an RB may contain 12 consecutive subcarriers inthe frequency domain and seven consecutive symbols in the time domain,for a total of 84 REs. For an extended cyclic prefix, an RB may contain12 consecutive subcarriers in the frequency domain and six consecutivesymbols in the time domain, for a total of 72 REs. The number of bitscarried by each RE depends on the modulation scheme.

Some of the REs may carry reference (pilot) signals (RS). The referencesignals may include positioning reference signals (PRS), trackingreference signals (TRS), phase tracking reference signals (PTRS),cell-specific reference signals (CRS), channel state informationreference signals (CSI-RS), demodulation reference signals (DMRS),primary synchronization signals (PSS), secondary synchronization signals(SSS), synchronization signal blocks (SSBs), sounding reference signals(SRS), etc., depending on whether the illustrated frame structure isused for uplink or downlink communication. FIG. 4 illustrates examplelocations of REs carrying reference signals (labeled “R”).

FIG. 5 is a graph 500 illustrating the channel impulse response of amultipath channel between a receiver device (e.g., any of the UEs orbase stations described herein) and a transmitter device (e.g., anyother of the UEs or base stations described herein), according toaspects of the disclosure. The channel impulse response represents theintensity of a radio frequency (RF) signal (e.g., PRS, PTRS, CSI-RS,DMRS, PSS, SSS, SRS, etc.) received through a multipath channel as afunction of time delay. Thus, the horizontal axis is in units of time(e.g., milliseconds) and the vertical axis is in units of signalstrength (e.g., decibels). Note that a multipath channel is a channelbetween a transmitter and a receiver over which an RF signal followsmultiple paths, or multipaths, due to transmission of the RF signal onmultiple beams and/or to the propagation characteristics of the RFsignal (e.g., reflection, refraction, etc.).

In the example of FIG. 5 , the receiver detects/measures multiple (four)clusters of channel taps. Each channel tap represents a multipath thatan RF signal followed between the transmitter and the receiver. That is,a channel tap represents the arrival of an RF signal on a multipath.Each cluster of channel taps indicates that the corresponding multipathsfollowed essentially the same path. There may be different clusters dueto the RF signal being transmitted on different transmit beams (andtherefore at different angles), or because of the propagationcharacteristics of RF signals (e.g., potentially following differentpaths due to reflections), or both.

All of the clusters of channel taps for a given RF signal represent themultipath channel (or simply channel) between the transmitter andreceiver. Under the channel illustrated in FIG. 5 , the receiverreceives a first cluster of two RF signals on channel taps at time T1, asecond cluster of five RF signals on channel taps at time T2, a thirdcluster of five RF signals on channel taps at time T3, and a fourthcluster of four RF signals on channel taps at time T4. In the example ofFIG. 5 , because the first cluster of RF signals at time T1 arrivesfirst, it is assumed to correspond to the RF signal transmitted on thetransmit beam aligned with the LOS, or the shortest, path. The thirdcluster at time T3 is comprised of the strongest RF signals, and maycorrespond to, for example, the RF signal transmitted on a transmit beamaligned with a non-line-of-sight (NLOS) path. Note that although FIG. 5illustrates clusters of two to five channel taps, as will beappreciated, the clusters may have more or fewer than the illustratednumber of channel taps.

NR supports a number of cellular network-based positioning technologies,including downlink-based, uplink-based, and downlink-and-uplink-basedpositioning methods. Downlink-based positioning methods include observedtime difference of arrival (OTDOA) in LTE, downlink time difference ofarrival (DL-TDOA) in NR, and downlink angle-of-departure (DL-AoD) in NR.In an OTDOA or DL-TDOA positioning procedure, a UE measures thedifferences between the times of arrival (ToAs) of reference signals(e.g., positioning reference signals (PRS)) received from pairs of basestations, referred to as reference signal time difference (RSTD) or timedifference of arrival (TDOA) measurements, and reports them to apositioning entity. More specifically, the UE receives the identifiers(IDs) of a reference base station (e.g., a serving base station) andmultiple non-reference base stations in assistance data. The UE thenmeasures the RSTD between the reference base station and each of thenon-reference base stations. Based on the known locations of theinvolved base stations and the RSTD measurements, the positioning entitycan estimate the UE's location.

For DL-AoD positioning, the positioning entity uses a beam report fromthe UE of received signal strength measurements of multiple downlinktransmit beams to determine the angle(s) between the UE and thetransmitting base station(s). The positioning entity can then estimatethe location of the UE based on the determined angle(s) and the knownlocation(s) of the transmitting base station(s).

Uplink-based positioning methods include uplink time difference ofarrival (UL-TDOA) and uplink angle-of-arrival (UL-AoA). UL-TDOA issimilar to DL-TDOA, but is based on uplink reference signals (e.g.,sounding reference signals (SRS)) transmitted by the UE. For UL-AoApositioning, one or more base stations measure the received signalstrength of one or more uplink reference signals (e.g., SRS) receivedfrom a UE on one or more uplink receive beams. The positioning entityuses the signal strength measurements and the angle(s) of the receivebeam(s) to determine the angle(s) between the UE and the basestation(s). Based on the determined angle(s) and the known location(s)of the base station(s), the positioning entity can then estimate thelocation of the UE.

Downlink-and-uplink-based positioning methods include enhanced cell-ID(E-CID) positioning and multi-round-trip-time (RTT) positioning (alsoreferred to as “multi-cell RTT”). In an RTT procedure, an initiator (abase station or a UE) transmits an RTT measurement signal (e.g., a PRSor SRS) to a responder (a UE or base station), which transmits an RTTresponse signal (e.g., an SRS or PRS) back to the initiator. The RTTresponse signal includes the difference between the ToA of the RTTmeasurement signal and the transmission time of the RTT response signal,referred to as the reception-to-transmission (Rx-Tx) time difference.The initiator calculates the difference between the transmission time ofthe RTT measurement signal and the ToA of the RTT response signal,referred to as the transmission-to-reception (Tx-Rx) time difference.The propagation time (also referred to as the “time of flight”) betweenthe initiator and the responder can be calculated from the Tx-Rx andRx-Tx time differences. Based on the propagation time and the knownspeed of light, the distance between the initiator and the responder canbe determined. For multi-RTT positioning, a UE performs an RTT procedurewith multiple base stations to enable its location to be determined(e.g., using multilateration) based on the known locations of the basestations. RTT and multi-RTT methods can be combined with otherpositioning techniques, such as UL-AoA and DL-AoD, to improve locationaccuracy.

The E-CID positioning method is based on radio resource management (RRM)measurements. In E-CID, the UE reports the serving cell ID, the timingadvance (TA), and the identifiers, estimated timing, and signal strengthof detected neighbor base stations. The location of the UE is thenestimated based on this information and the known locations of the basestation(s).

To assist positioning operations, a location server (e.g., locationserver 230, LMF 270, SLP 272) may provide assistance data to the UE. Forexample, the assistance data may include identifiers of the basestations (or the cells/TRPs of the base stations) from which to measurereference signals, the reference signal configuration parameters (e.g.,the number of consecutive positioning subframes, periodicity ofpositioning subframes, muting sequence, frequency hopping sequence,reference signal identifier, reference signal bandwidth, etc.), and/orother parameters applicable to the particular positioning method.Alternatively, the assistance data may originate directly from the basestations themselves (e.g., in periodically broadcasted overheadmessages, etc.). In some cases, the UE may be able to detect neighbornetwork nodes itself without the use of assistance data.

In the case of an OTDOA or DL-TDOA positioning procedure, the assistancedata may further include an expected RSTD value and an associateduncertainty, or search window, around the expected RSTD. In some cases,the value range of the expected RSTD may be +/−500 microseconds (μs). Insome cases, when any of the resources used for the positioningmeasurement are in FR1, the value range for the uncertainty of theexpected RSTD may be +/−32 μs. In other cases, when all of the resourcesused for the positioning measurement(s) are in FR2, the value range forthe uncertainty of the expected RSTD may be +/−8 μs.

A location estimate may be referred to by other names, such as aposition estimate, location, position, position fix, fix, or the like. Alocation estimate may be geodetic and comprise coordinates (e.g.,latitude, longitude, and possibly altitude) or may be civic and comprisea street address, postal address, or some other verbal description of alocation. A location estimate may further be defined relative to someother known location or defined in absolute terms (e.g., using latitude,longitude, and possibly altitude). A location estimate may include anexpected error or uncertainty (e.g., by including an area or volumewithin which the location is expected to be included with some specifiedor default level of confidence).

FIG. 6 illustrates a time difference of arrival (TDOA)-based positioningprocedure in an example wireless communications system 600, according toaspects of the disclosure. The TDOA-based positioning procedure may bean observed time difference of arrival (OTDOA) positioning procedure, asin LTE, or a downlink time difference of arrival (DL-TDOA) positioningprocedure, as in 5G NR. In the example of FIG. 6 , a UE 604 (e.g., anyof the UEs described herein) is attempting to calculate an estimate ofits location (referred to as “UE-based” positioning), or assist anotherentity (e.g., a base station or core network component, another UE, alocation server, a third party application, etc.) to calculate anestimate of its location (referred to as “UE-assisted” positioning). TheUE 604 may communicate with (e.g., send information to and receiveinformation from) one or more of a plurality of base stations 602 (e.g.,any combination of base stations described herein), labeled “BS1” 602-1,“BS2” 602-2, and “BS3” 602-3.

To support location estimates, the base stations 602 may be configuredto broadcast positioning reference signals (e.g., PRS, TRS, CRS, CSI-RS,etc.) to a UE 604 in their coverage areas to enable the UE 604 tomeasure characteristics of such reference signals. In a TDOA-basedpositioning procedure, the UE 604 measures the time difference, known asthe reference signal time difference (RSTD) or TDOA, between specificdownlink reference signals (e.g., PRS, TRS, CRS, CSI-RS, etc.)transmitted by different pairs of base stations 602, and either reportsthese RSTD measurements to a location server (e.g., location server 230,LMF 270, SLP 272) or computes a location estimate itself from the RSTDmeasurements.

Generally, RSTDs are measured between a reference cell (e.g., a cellsupported by base station 602-1 in the example of FIG. 6 ) and one ormore neighbor cells (e.g., cells supported by base stations 602-2 and602-3 in the example of FIG. 6 ). The reference cell remains the samefor all RSTDs measured by the UE 604 for any single positioning use ofTDOA and would typically correspond to the serving cell for the UE 604or another nearby cell with good signal strength at the UE 604. In anaspect, the neighbor cells would normally be cells supported by basestations different from the base station for the reference cell, and mayhave good or poor signal strength at the UE 604. The locationcomputation can be based on the measured RSTDs and knowledge of theinvolved base stations' 602 locations and relative transmission timing(e.g., regarding whether base stations 602 are accurately synchronizedor whether each base station 602 transmits with some known time offsetrelative to other base stations 602).

To assist TDOA-based positioning operations, the location server (e.g.,location server 230, LMF 270, SLP 272) may provide assistance data tothe UE 604 for the reference cell and the neighbor cells relative to thereference cell. For example, the assistance data may include identifiers(e.g., PCI, VCI, CGI, etc.) for each cell of a set of cells that the UE604 is expected to measure (here, cells supported by the base stations602). The assistance data may also provide the center channel frequencyof each cell, various reference signal configuration parameters (e.g.,the number of consecutive positioning slots, periodicity of positioningslots, muting sequence, frequency hopping sequence, reference signalidentifier, reference signal bandwidth), and/or other cell relatedparameters applicable to TDOA-based positioning procedures. Theassistance data may also indicate the serving cell for the UE 604 as thereference cell.

In some cases, the assistance data may also include “expected RSTD”parameters, which provide the UE 604 with information about the RSTDvalues the UE 604 is expected to measure between the reference cell andeach neighbor cell at its current location, together with an uncertaintyof the expected RSTD parameter. The expected RSTD, together with theassociated uncertainty, may define a search window for the UE 604 withinwhich the UE 604 is expected to measure the RSTD value. In some cases,the value range of the expected RSTD may be +/−500 microseconds (μs). Insome cases, when any of the resources used for the positioningmeasurement are in FR1, the value range for the uncertainty of theexpected RSTD may be +/−32 μs. In other cases, when all of the resourcesused for the positioning measurement(s) are in FR2, the value range forthe uncertainty of the expected RSTD may be +/−8 μs.

TDOA assistance information may also include positioning referencesignal configuration information parameters, which allow the UE 604 todetermine when a positioning reference signal occasion will occur onsignals received from various neighbor cells relative to positioningreference signal occasions for the reference cell, and to determine thereference signal sequence transmitted from the various cells in order tomeasure a reference signal time of arrival (ToA) or RSTD.

In an aspect, while the location server (e.g., location server 230, LMF270, SLP 272) may send the assistance data to the UE 604, alternatively,the assistance data can originate directly from the base stations 602themselves (e.g., in periodically broadcasted overhead messages, etc.).Alternatively, the UE 604 can detect neighbor base stations itselfwithout the use of assistance data.

The UE 604 (e.g., based in part on the assistance data, if provided) canmeasure and (optionally) report the RSTDs between reference signalsreceived from pairs of base stations 602. Using the RSTD measurements,the known absolute or relative transmission timing of each base station602, and the known location(s) of the reference and neighbor basestations 602, the network (e.g., location server 230/LMF 270/SLP 272, abase station 602) or the UE 604 can estimate the location of the UE 604.More particularly, the RSTD for a neighbor cell “k” relative to areference cell “Ref” may be given as (ToA_k-ToA_Ref). In the example ofFIG. 6 , the measured RSTDs between the reference cell of base station602-1 and the cells of neighbor base stations 602-2 and 602-3 may berepresented as T2-T1 and T3-T1, where T1, T2, and T3 represent the ToAof a reference signal from the base station 602-1, 602-2, and 602-3,respectively. The UE 604 (if it is not the positioning entity) may thensend the RSTD measurements to the location server or other positioningentity. Using (i) the RSTD measurements, (ii) the known absolute orrelative transmission timing of each base station 602, (iii) the knownlocation(s) of the base stations 602, and/or (iv) directional referencesignal characteristics, such as the direction of transmission, the UE's604 location may be determined (either by the UE 604 or the locationserver).

In an aspect, the location estimate may specify the location of the UE604 in a two-dimensional (2D) coordinate system; however, the aspectsdisclosed herein are not so limited, and may also be applicable todetermining location estimates using a three-dimensional (3D) coordinatesystem, if the extra dimension is desired. Additionally, while FIG. 6illustrates one UE 604 and three base stations 602, as will beappreciated, there may be more UEs 604 and more base stations 602.

Still referring to FIG. 6 , when the UE 604 obtains a location estimateusing RSTDs, the necessary additional data (e.g., the base stations' 602locations and relative transmission timing) may be provided to the UE604 by the location server. In some implementations, a location estimatefor the UE 604 may be obtained (e.g., by the UE 604 itself or by thelocation server) from RSTDs and from other measurements made by the UE604 (e.g., measurements of signal timing from global positioning system(GPS) or other global navigation satellite system (GNSS) satellites). Inthese implementations, known as hybrid positioning, the RSTDmeasurements may contribute towards obtaining the UE's 604 locationestimate but may not wholly determine the location estimate.

FIG. 7 is a diagram 700 illustrating example measurement timings of aTDOA-based positioning procedure, according to aspects of thedisclosure. The TDOA between two network nodes (e.g., base stations) canbe obtained from RSTD measurements performed by a UE. During a firststage, illustrated in FIG. 7 , the UE measures RSTDs between pairs ofbase stations, as described above with reference to FIG. 6 . In theexample of FIG. 7 , the UE measures the ToAs of DL-RS (e.g., PRS) fromeach of three base stations (denoted as “BS1,” “BS2,” and “BS3”). Eachbase station transmits its respective DL-RS at the same time,illustrated by the first vertical dashed line. Alternatively, the basestations may transmit their DL-RS at different times, so long as thedifference, or offset, is known to the UE (or other positioning entity).

The first base station (BS1) is the reference base station, and as such,the UE can calculate the RSTDs for the second and third base stations(BS2 and BS3) based on the ToA of the DL-RS from the first base station.Specifically, the UE calculates the RSTD between the first base station(BS1) and the second base station (BS2) as the difference between theToA of the DL-RS from the first base station (labeled “ToA_BS1”) and theToA of the DL-RS from the second base station (labeled “ToA_BS2”). TheRSTD for the second base station is labeled “RSTD_BS2.” The UEcalculates the RSTD between the first base station (BS1) and the thirdbase station (BS3) as the difference between the ToA of the DL-RS fromthe first base station (labeled “ToA_BS1”) and the ToA of the DL-RS fromthe third base station (labeled “ToA_BS3”). The RSTD for the third basestation is labeled “RSTD_BS3.”

In a DL-TDOA positioning procedure, the UE may not know when the DL-RSsignals are transmitted (indicated by the first vertical dashed line inFIG. 7 ). As such, the UE may not be able to estimate the propagationtime between itself and the different base stations. It can, however,estimate the RSTDs (e.g., RSTD_BS2 and RSTD_BS3 in FIG. 7 ) for thenon-reference base stations (e.g., BS2 and BS3 and FIG. 7 ), as these donot require knowledge of the transmission time of the DL-RS, only thatthey were transmitted at the same time or with some known offset.

At a second stage of a DL-TDOA positioning procedure, for UE-assistedpositioning, the UE reports the calculated RSTD measurements to thelocation server (which may be located at the serving base station, thecore network, or external to the core network). The location server (orother positioning entity) can use the RSTD measurements to determinehyperbolas around the known locations of the involved base stations(e.g., BS1, BS2, and BS3 in FIG. 7 ). The location of the UE isdetermined as the intersection of the hyperbolas.

In greater detail, the following equations represent the range (R), ordistance, from each involved base station (e.g., BS1, BS2, and BS3 inFIG. 7 ) to the UE as the propagation time (T_prop) between the basestation and the UE multiplied by the speed of light (c).R _(BS1↔UE) =c·T_prop_(BS1)R _(BS2↔UE) =c·T_prop_(BS2)R _(BS3↔UE) =c·T_prop_(BS3)

However, the above ranges are unknown. As such, the location server usesthe following equations to determine the hyperbolas on which the UE maybe located.R _(BS2↔UE) −R _(BS1↔UE) =c·RSTD _(BS2)R _(BS3↔UE) −R _(BS1↔UE) =c·RSTD _(BS3)

FIG. 8 is a diagram 800 illustrating example hyperbolas that satisfy theabove equations. The example of FIG. 8 is related to the example of FIG.7 , and therefore illustrates three base stations labeled “BS1,” “BS2,”and “BS3” that correspond to the three base stations in the example ofFIG. 7 . As shown in FIG. 8 , any point P on the half part of hyperbola810 satisfies the following equations (where subscripts are indicated inFIG. 8 by underscores):R _(BS2↔P) −R _(BS1↔P) =c·RSTD _(BS2)R _(BS2↔P) >R _(BS1↔P)

Similarly, any point P on the half part of hyperbola 820 satisfies thefollowing equations:R _(BS3↔P) −R _(BS1↔P) =c·RSTD _(BS3)R _(BS3↔P) >R _(BS1↔P)

As shown in FIG. 8 , the UE is located on the intersection of the twohyperbolas 810 and 820. Thus, with a DL-TDOA positioning method, onlythree base stations and three ToA measurements (for the two RSTDs) areneeded for a two-dimensional location estimate of the UE, provided thetransmitting base stations are synchronized (or have a known offset).

Wireless communication signals (e.g., RF signals configured to carryOFDM symbols) transmitted between a UE and a base station can be reusedfor environment sensing. Using wireless communication signals forenvironment sensing can be regarded as consumer-level radar withadvanced detection capabilities that enable, among other things,touchless/device-free interaction with a device/system. The wirelesscommunication signals may be cellular communication signals, such as LTEor NR signals, WLAN signals, etc. High-frequency communication signals,such as mmW RF signals, are especially beneficial to use as radarsignals because the higher frequency provides more accurate range(distance) detection.

Possible use cases of RF sensing include health monitoring use cases,such as heartbeat detection, respiration rate monitoring, and the like,gesture recognition use cases, such as human activity recognition,keystroke detection, sign language recognition, and the like, contextualinformation acquisition use cases, such as location detection/tracking,direction finding, range estimation, and the like, and automotive radaruse cases, such as smart cruise control, collision avoidance, and thelike.

The present disclosure provides techniques for using wirelesscommunication signals to detect the location of a device-free object(i.e., an object that does not itself transmit wireless signals) or anon-participating object (i.e., an object or device that may be capableof wireless communication but is not participating in a positioningsession to be located). At a high level, a UE can receive downlinkwireless communication signals from a base station and identifycharacteristics of the signals that indicate whether or not the signalsreflected off a device-free/non-participating object on their way fromthe base station to the UE. The UE can report measurements of thesecharacteristics to the location server, and the location server can usethe measurements to locate the device-free/non-participating objectusing DL-TDOA techniques.

FIGS. 9A and 9B illustrate a comparison between a conventionalpositioning procedure scenario that only locates a UE and a scenario inwhich both a UE and a device-free/non-participating object can belocated. Specifically, FIG. 9A is a diagram 910 illustrating a scenarioin which three base stations (labeled “BS1,” “BS2,” and “BS3”) transmitRF signals (e.g., PRS) to a UE. The UE can measure the ToAs of these RFsignals and calculate RSTD measurements based on the ToAs, as describedabove with reference to FIGS. 6 and 7 . The location of the UE can thenbe determined as described above with reference to FIGS. 6 and 8 .

FIG. 9B is a diagram 950 illustrating a scenario in which the same threebase stations (labeled “BS1,” “BS2,” and “BS3”) as in FIG. 9A transmitRF signals (e.g., PRS) to the UE, but some of the RF signals reflect offa device-free/non-participating object. The UE can measure the ToAs ofthe RF signals received directly from the base stations (illustrated assolid lines) and the ToAs of the RF signals reflected from thedevice-free object (illustrated as dashed lines).

More specifically, as described above, a transmitter (e.g., a basestation) may transmit a single RF signal or multiple RF signals to areceiver (e.g., a UE). However, the receiver may receive multiple RFsignals corresponding to each transmitted RF signal due to thepropagation characteristics of RF signals through multipath channels.Each path may be associated with a cluster of one or more channel taps.Generally, the time at which the receiver detects the first cluster ofchannel taps is considered the ToA of the RF signal on the LOS path(e.g., “Cluster1” in FIG. 5 ). Later clusters of channel taps (e.g.,“Cluster2,” “Cluster3,” “Cluster4” in FIG. 5 ) are considered to havereflected off objects between the transmitter and the receiver andtherefore to have followed NLOS paths between the transmitter and thereceiver.

Thus, referring back to FIG. 9B, the solid lines represent RF signalsthat followed the LOS paths between the respective base stations and theUE, and the dashed lines represent the RF signals that followed NLOSpaths between the respective base station and the UE due to reflectingoff the device-free object. The base stations may have transmittedmultiple RF signals, some of which followed the LOS paths and others ofwhich followed the NLOS paths. Alternatively, the base stations may haveeach transmitted a single RF signal in a broad enough beam that aportion of the RF signal followed the LOS path and a portion of the RFsignal followed the NLOS path.

FIG. 10 is a diagram 1000 illustrating measurements performed by a UE toenable the detection of a device-free/non-participating object,according to aspects of the disclosure. In the example of FIG. 10 , likethe example of FIG. 7 , the UE measures the ToAs of DL-RS (e.g., PRS)from each of three base stations (illustrated as “BS1,” “BS2,” and“BS3”). Each base station transmits its respective DL-RS at the sametime, illustrated by the first vertical dashed line. Alternatively, thebase stations may transmit their DL-RS at different times, so long asthe difference, or offset, is known to the UE (or other positioningentity).

In the example of FIG. 10 , the UE measures the ToA of the DL-RS fromeach base station that followed the LOS path (illustrated by the firstvertical arrow in each timeline). In addition, the UE measures the ToAof the DL-RS from each base station that followed a NLOS path(illustrated by the second vertical arrow in each timeline). The DL-RSon the NLOS paths are assumed to have reflected off adevice-free/non-participating object. The UE can then calculate therespective RSTDs.

In the example of FIG. 10 , the first base station (BS1) is thereference base station, and as such, the UE can calculate the RSTDs forthe second and third base stations (BS2 and BS3) based on the ToAs ofthe DL-RS that followed the LOS paths, as described above with referenceto FIG. 7 . These RSTDs are labeled “RSTD_D,BS2” and “RSTD_D,BS3.” Inaddition, the UE calculates additional RSTDs for the NLOS paths.Specifically, the UE calculates a first additional RSTD for the firstbase station (BS1) as the difference between the ToA of the LOS path(the first vertical arrow) and the ToA of the NLOS path (the secondvertical arrow). This RSTD is labeled RSTD_R,BS1. The UE calculates asecond additional RSTD for the second base station (BS2) as thedifference between the ToA of the LOS path for the first base stationand the ToA of the NLOS path for the second base station. This RSTD islabeled RSTD_R,BS2. The UE calculates a third additional RSTD for thethird base station (BS3) as the difference between the ToA of the LOSpath for the first base station and the ToA of the NLOS path for thethird base station. This RSTD is labeled RSTD_R,BS3. The UE can thenreport these measurements to the location server.

There are different options regarding which RSTD measurements the UEreports to the location server. As a first option, the UE may report allof the calculated RSTD values. For example, with reference to FIG. 10 ,the UE may report the set of LOS path RSTDs {RSTD_D,BS1, RSTD_D,BS2} andthe set of NLOS path RSTDs {RSTD_R,BS1, RSTD_R,BS2, RSTD_R,BS3}. As asecond option, the UE may report the set of LOS path RSTDs and thedifferences between the NLOS path RSTDs. For example, with reference toFIG. 10 , the UE may report the set of LOS path RSTDs {RSTD_D,BS1,RSTD_D,BS2} and the set of NLOS path RSTD differences{RSTD_R,BS2-RSTD_R,BS1, RSTD_R,BS3-RSTD_R,BS1}. This option can reducefeedback overhead compared to the first option.

As a third option, the UE may report only the difference between theNLOS RSTDs. For example, with reference to FIG. 10 , the UE may reportthe set of differences {RSTD_R,BS2-RSTD_R,BS1, RSTD_R,BS3-RSTD_R,BS1}.The third option can be used for the special case where the locationserver does not need to determine the UE's location, and instead, onlyneeds to detect device-free objects. In this case, the third option canfurther reduce feedback overhead.

FIG. 11 is a diagram 1100 of an example network in which three basestations (labeled “BS1,” “BS2,” and “BS3”) transmit RF signals to a UEthat are reflected off a device-free/non-participating object (labeled“Target”), according to aspects of the disclosure. The distance betweenthe first base station (BS1) and the UE is represented as R_(BS1↔UE)(with subscripts indicated in FIG. 11 with underscores), the distancebetween the second base station (BS2) and the UE is represented asR_(BS2↔UE), and the distance between the third base station (BS3) andthe UE is represented as R_(BS3↔UE). The distance between the first basestation and the target device-free/non-participating object isrepresented as R_(BS1↔target), the distance between the second basestation and the target device-free/non-participating object isrepresented as R_(BS2↔target), and the distance between the third basestation and the target device-free/non-participating object isrepresented as R_(BS3↔target).

Based on these distances, the following equations are true:R _(BS2↔UE) −R _(BS1↔UE) =c·RSTD _(BS2)R _(BS3↔UE) −R _(BS1↔UE) =c·RSTD _(BS3)R _(BS1↔target) +R _(target↔UE) −R _(BS1↔UE) =c·RSTD _(R,BS1)R _(BS2↔target) +R _(target↔UE) −R _(BS1↔UE) =c·RSTD _(R,BS2)R _(BS3↔target) +R _(target↔UE) −R _(BS1↔UE) =c·RSTD _(R,BS3)

Using the first two equations above, the location server (or otherpositioning entity) can determine the location of the UE as lying at theintersection of two hyperbolas, as is known in the art and describedabove with reference to FIG. 8 . Using the last three equations above,the location server can determine the location of thedevice-free/non-participating object as lying at the intersection ofthree ellipses whose foci are each base station and the UE. Morespecifically, the distance between the UE and the reference base station(e.g., BS1), represented as R_(BS1↔UE), can be obtained from aconventional DL-TDOA procedure. That is, the UE location can beestimated using a DL-TDOA procedure, as shown in FIG. 8 , and once theUE location is known, then the distance between the UE and any of theinvolved base stations can be calculated based on the known locations ofthe base stations. Then, the distance between the first base station andthe device-free object plus the distance between the UE and thedevice-free object (R_(BS1↔target)+R_(target↔UE)), the distance betweenthe second base station and the device-free object plus the distancebetween the UE and the device-free object(R_(BS2↔target)+R_(target↔UE)), and the distance between the third basestation and the device-free object plus the distance between the UE andthe device-free object (R_(BS3↔target)+R_(target↔UE)) can be obtainedfrom the NLOS path RSTDs (RSTD_(R,BS1), RSTD_(R,BS2), and RSTD_(R,BS3)).The three ellipses can be drawn by using the foregoing sums (i.e.,R_(BS1↔target)+R_(target↔UE), R_(BS2↔target)+R_(target↔UE), andR_(BS3↔target)+R_(target↔UE)), the location of the UE, and the locationsof the three base stations.

FIG. 12 is a diagram 1200 of an example network of three base stations(labeled “BS1,” “BS2,” and “BS3”), a UE, and a device-free object(labeled “Target”), according to aspects of the disclosure. Threeellipses are illustrated in FIG. 12 that were calculated as describedabove. As shown, the foci of each ellipse are a base station and the UE.As illustrated in FIG. 12 , any point P on the ellipse associated withthe third base station (BS3) satisfies the following equation (withsubscripts indicated in FIG. 12 with underscores):R _(BS3↔P) +R _(P↔UE) =R _(BS3↔target) +R _(target↔UE) =c·RSTD _(R,BS3)+R _(BS1↔UE)

Similarly, any point P on the ellipses associated with the first andsecond base stations satisfy the following equations:R _(BS1↔P) +R _(P↔UE) =R _(BS1↔target) +R _(target↔UE) =c·RSTD _(R,BS1)+R _(BS1↔UE)R _(BS2↔P) +R _(P↔UE) =R _(BS2↔target) +R _(target↔UE) =c·RSTD _(R,BS2)+R _(BS1↔UE)

The above approach can be used when the UE reports RSTD measurements asdescribed above for the first two reporting options. For the thirdreporting option, where the UE only reports the differences between theNLOS path RSTDs, a different approach can be used. In this case, thetarget device-free/non-participating object can be located at theintersecting point of three hyperbolas whose foci are the involved basestations; the UE's location is not needed. Specifically, the differencebetween the distance between the second base station and the device-freeobject and the distance between the first base station and thedevice-free object (R_(BS2↔target)−R_(BS1↔target)), the differencebetween the distance between the third base station and the device-freeobject and the distance between the first base station and thedevice-free object (R_(BS3↔target)−R_(BS1↔target)), and the differencebetween the distance between the second base station and the device-freeobject and the distance between the third base station and thedevice-free object (R_(BS2↔target)−R_(BS3↔target)) can be obtained fromNLOS path RSTD differences for the three base stations(RSTD_(R,BS2)−RSTD_(R,BS1), RSTD_(R,BS3)−RSTD_(R,BS1)). The threehyperbolas can be drawn using the foregoing differences (i.e.,R_(BS2↔target)−R_(BS1↔target), R_(BS3↔target)−R_(BS1↔target), andR_(BS2↔target)−R_(BS3↔target)) and the locations of the three basestations.

FIG. 13 is a diagram 1300 of an example network of three base stations(labeled “BS1,” “BS2,” and “BS3”), a UE, and adevice-free/non-participating object (labeled “Target”), according toaspects of the disclosure. Three hyperbolas are illustrated in FIG. 13that were calculated as described above. As shown, the foci of eachhyperbola is a base station. As illustrated in FIG. 13 , any point P onthe hyperbola associated with the first base station (BS1) satisfies thefollowing equation (with subscripts indicated in FIG. 13 withunderscores):R _(BS3↔P) −R _(BS1↔P) =R _(BS3↔target) −R _(BS1↔target) =c(RSTD_(R,BS3) −RSTD _(R,BS1))where R_(BS3↔P)>R_(BS1↔P).

As will be appreciated, although the foregoing examples described onlythree involved base stations, there may be more than three involved basestations. In addition, while the examples describe a single targetdevice-free/non-participating object, there may be multipledevice-free/non-participating objects. In that case, the UE cancalculate and report additional RSTDs for each detected cluster ofchannel taps for a given DL-RS from a base station. For example, ifthere are multiple objects around the transmitters (e.g., base stations)and receiver (e.g., UE), the receiver may detect/measure multipledominant multipath signals, such as a second arrival path, a thirdarrival path, a fourth arrival path, and so on. If the receiver reportsthe observed RSTDs for the second, third, fourth, and so on paths, thenetwork (e.g., the location server) can process the reported RSTDs todetect multiple target objects. The receiver may not need to distinguishwhich path is from which object—it may be up to network implementationregarding how to process the reported quantities to detect multipletargets.

FIG. 14 illustrates an example method 1400 of wireless sensing,according to aspects of the disclosure. In an aspect, method 1400 may beperformed by a UE (e.g., any of the UEs described herein).

At 1410, the UE measures at least an LOS path (e.g., the solid line fromBS1 in FIG. 9B) and an NLOS path (e.g., the dashed line from BS1 in FIG.9B) of a first DL-PRS from a first TRP (e.g., BS1 in FIG. 9B). In anaspect, operation 1410 may be performed by the one or more WWANtransceivers 310, the one or more processors 332, memory 340, and/orsensing component 342, any or all of which may be considered means forperforming this operation.

At 1420, the UE measures at least an LOS path (e.g., the solid line fromBS2 in FIG. 9B) and an NLOS path (e.g., the dashed line from BS2 in FIG.9B) of a second DL-PRS from a second TRP (e.g., BS2 in FIG. 9B). In anaspect, operation 1420 may be performed by the one or more WWANtransceivers 310, the one or more processors 332, memory 340, and/orsensing component 342, any or all of which may be considered means forperforming this operation.

At 1430, the UE measures at least an LOS path (e.g., the solid line fromBS3 in FIG. 9B) and an NLOS path (e.g., the dashed line from BS3 in FIG.9B) of a third DL-PRS from a third TRP (e.g., BS3 in FIG. 9B). In anaspect, operation 1430 may be performed by the one or more WWANtransceivers 310, the one or more processors 332, memory 340, and/orsensing component 342, any or all of which may be considered means forperforming this operation.

At 1440, the UE enables a location of a non-participating target object(e.g., the device-free/non-participating object in FIG. 9B) to bedetermined based, at least in part, on a first RSTD between a ToA of theLOS path of the first DL-PRS and a ToA of the NLOS path of the firstDL-PRS (e.g., RSTD_R,BS1 in FIG. 10 ), a second RSTD between the ToA ofthe LOS path of the first DL-PRS and a ToA of the NLOS path of thesecond DL-PRS (e.g., RSTD_R,BS2 in FIG. 10 ), and a third RSTD betweenthe ToA of the LOS path of the first DL-PRS and a ToA of the NLOS pathof the third DL-PRS (e.g., RSTD_R,BS3 in FIG. 10 ), wherein thenon-participating target object does not participate in determining thelocation of the non-participating target object. In an aspect, operation1440 may be performed by the one or more WWAN transceivers 310, the oneor more processors 332, memory 340, and/or sensing component 342, any orall of which may be considered means for performing this operation.

As will be appreciated, a technical advantage of the method 1400 is theability to detect the location of device-free/non-participating objectsusing TDOA-based positioning techniques.

In the detailed description above it can be seen that different featuresare grouped together in examples. This manner of disclosure should notbe understood as an intention that the example clauses have morefeatures than are explicitly mentioned in each clause. Rather, thevarious aspects of the disclosure may include fewer than all features ofan individual example clause disclosed. Therefore, the following clausesshould hereby be deemed to be incorporated in the description, whereineach clause by itself can stand as a separate example. Although eachdependent clause can refer in the clauses to a specific combination withone of the other clauses, the aspect(s) of that dependent clause are notlimited to the specific combination. It will be appreciated that otherexample clauses can also include a combination of the dependent clauseaspect(s) with the subject matter of any other dependent clause orindependent clause or a combination of any feature with other dependentand independent clauses. The various aspects disclosed herein expresslyinclude these combinations, unless it is explicitly expressed or can bereadily inferred that a specific combination is not intended (e.g.,contradictory aspects, such as defining an element as both an insulatorand a conductor). Furthermore, it is also intended that aspects of aclause can be included in any other independent clause, even if theclause is not directly dependent on the independent clause.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of wireless sensing performed by a user equipment(UE), comprising: measuring at least a line-of-sight (LOS) path and anon-line-of-sight (NLOS) path of a first downlink positioning referencesignal (DL-PRS) from a first transmission-reception point (TRP);measuring at least an LOS path and an NLOS path of a second DL-PRS froma second TRP; measuring at least an LOS path and an NLOS path of a thirdDL-PRS from a third TRP; and enabling a location of a non-participatingtarget object to be determined based, at least in part, on a firstreference signal time difference (RSTD) between a time of arrival (ToA)of the LOS path of the first DL-PRS and a ToA of the NLOS path of thefirst DL-PRS, a second RSTD between the ToA of the LOS path of the firstDL-PRS and a ToA of the NLOS path of the second DL-PRS, and a third RSTDbetween the ToA of the LOS path of the first DL-PRS and a ToA of theNLOS path of the third DL-PRS, wherein the non-participating targetobject does not participate in determining the location of thenon-participating target object.

Clause 2. The method of clause 1, wherein enabling the location of thenon-participating target object to be determined comprises: reporting,to a location server, at least the first RSTD, the second RSTD, and thethird RSTD.

Clause 3. The method of any of clauses 1 to 2, wherein: the location ofthe non-participating target object is determined to be at anintersection of a first ellipse, a second ellipse, and a third ellipse,first and second foci of the first ellipse correspond to a location ofthe first TRP and a location of the UE, first and second foci of thesecond ellipse correspond to a location of the second TRP and thelocation of the UE, and first and second foci of the third ellipsecorrespond to a location of the third TRP and the location of the UE.

Clause 4. The method of clause 3, wherein: the first ellipse isdetermined based on a distance between the first TRP and thenon-participating target object, a distance between the UE and thenon-participating target object, the location of the first TRP, and thelocation of the UE, the second ellipse is determined based on a distancebetween the second TRP and the non-participating target object, thedistance between the UE and the non-participating target object, thelocation of the second TRP, and the location of the UE, and the thirdellipse is determined based on a distance between the third TRP and thenon-participating target object, the distance between the UE and thenon-participating target object, the location of the third TRP, and thelocation of the UE.

Clause 5. The method of clause 4, wherein: the distance between thefirst TRP and the non-participating target object plus the distancebetween the UE and the non-participating target object is determinedbased on the first RSTD, the distance between the second TRP and thenon-participating target object plus the distance between the UE and thenon-participating target object is determined based on the second RSTD,and the distance between the third TRP and the non-participating targetobject plus the distance between the UE and the non-participating targetobject is determined based on the third RSTD.

Clause 6. The method of any of clauses 3 to 5, wherein the location ofthe UE is determined based on an RSTD between the ToA of the LOS path ofthe first DL-PRS and a ToA of the LOS path of the second DL-PRS and anRSTD between the ToA of the LOS path of the first DL-PRS and a ToA ofthe LOS path of the third DL-PRS.

Clause 7. The method of any of clauses 1 to 6, wherein enabling thelocation of the non-participating target object to be determinedcomprises: reporting, to a location server, at least a differencebetween the second RSTD and the first RSTD and a difference between thethird RSTD and the first RSTD.

Clause 8. The method of any of clauses 1 to 7, wherein: the location ofthe non-participating target object is determined to be at anintersection of a first hyperbola, a second hyperbola, and a thirdhyperbola, a foci of the first hyperbola is a location of the first TRP,a foci of the second hyperbola is a location of the second TRP, and afoci of the third hyperbola is a location of the third TRP.

Clause 9. The method of clause 8, wherein: the first hyperbola isdetermined based on a difference between a distance between the secondTRP and the non-participating target object and a distance between thefirst TRP and the non-participating target object, the location of thefirst TRP, and the location of the second TRP, the second hyperbola isdetermined based on a difference between a distance between the thirdTRP and the non-participating target object and the distance between thefirst TRP and the non-participating target object, the location of thefirst TRP, and the location of the third TRP, and the third hyperbola isdetermined based on a difference between the distance between the secondTRP and the non-participating target object and the distance between thethird TRP and the non-participating target object, the location of thesecond TRP, and the location of the third TRP.

Clause 10. The method of clause 9, wherein the difference between thedistance between the second TRP and the non-participating target objectand the distance between the first TRP and the non-participating targetobject, the difference between the distance between the third TRP andthe non-participating target object and the distance between the firstTRP and the non-participating target object, and the difference betweenthe distance between the second TRP and the non-participating targetobject and the distance between the third TRP and the non-participatingtarget object are determined based on a difference between the secondRSTD and the first RSTD and a difference between the third RSTD and thefirst RSTD.

Clause 11. The method of any of clauses 1 to 10, further comprising:reporting, to a location server, at least an RSTD between the ToA of theLOS path of the first DL-PRS and a ToA of the LOS path of the secondDL-PRS and an RSTD between the ToA of the LOS path of the first DL-PRSand a ToA of the LOS path of the third DL-PRS to enable the locationserver to determine a location of the UE.

Clause 12. The method of any of clauses 1 to 11, wherein enabling thelocation of the non-participating target object to be determinedcomprises: determining the location of the non-participating targetobject based on the first RSTD between the ToA of the LOS path of thefirst DL-PRS and the ToA of the NLOS path of the first DL-PRS, thesecond RSTD between the ToA of the LOS path of the first DL-PRS and theToA of the NLOS path of the second DL-PRS, and the third RSTD betweenthe ToA of the LOS path of the first DL-PRS and the ToA of the NLOS pathof the third DL-PRS.

Clause 13. The method of clause 12, further comprising: receiving alocation of the first TRP, a location of the second TRP, and a locationof the third TRP, wherein determining the location of thenon-participating target object is further based on the location of thefirst TRP, the location of the second TRP, and the location of thirdTRP.

Clause 14. An apparatus comprising a memory, at least one transceiver,and at least one processor communicatively coupled to the memory and theat least one transceiver, the memory, the at least one transceiver, andthe at least one processor configured to perform a method according toany of clauses 1 to 13.

Clause 15. An apparatus comprising means for performing a methodaccording to any of clauses 1 to 13.

Clause 16. A non-transitory computer-readable medium storingcomputer-executable instructions, the computer-executable comprising atleast one instruction for causing a computer or processor to perform amethod according to any of clauses 1 to 13.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an ASIC, a field-programmable gate array (FPGA), or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,for example, a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An example storage medium is coupled to the processor such thatthe processor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal (e.g., UE). In thealternative, the processor and the storage medium may reside as discretecomponents in a user terminal.

In one or more example aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method of wireless sensing performed by a userequipment (UE), comprising: measuring at least a line-of-sight (LOS)path and a non-line-of-sight (NLOS) path of a first downlink positioningreference signal (DL-PRS) from a first transmission-reception point(TRP); measuring at least an LOS path and an NLOS path of a secondDL-PRS from a second TRP; measuring at least an LOS path and an NLOSpath of a third DL-PRS from a third TRP; and enabling a location of anon-participating target object to be determined based, at least inpart, on a first reference signal time difference (RSTD) between a timeof arrival (ToA) of the LOS path of the first DL-PRS and a ToA of theNLOS path of the first DL-PRS, a second RSTD between the ToA of the LOSpath of the first DL-PRS and a ToA of the NLOS path of the secondDL-PRS, and a third RSTD between the ToA of the LOS path of the firstDL-PRS and a ToA of the NLOS path of the third DL-PRS, wherein thenon-participating target object does not participate in determining thelocation of the non-participating target object.
 2. The method of claim1, wherein enabling the location of the non-participating target objectto be determined comprises: reporting, to a location server, at leastthe first RSTD, the second RSTD, and the third RSTD.
 3. The method ofclaim 1, wherein: the location of the non-participating target object isdetermined to be at an intersection of a first ellipse, a secondellipse, and a third ellipse, first and second foci of the first ellipsecorrespond to a location of the first TRP and a location of the UE,first and second foci of the second ellipse correspond to a location ofthe second TRP and the location of the UE, and first and second foci ofthe third ellipse correspond to a location of the third TRP and thelocation of the UE.
 4. The method of claim 3, wherein: the first ellipseis determined based on a distance between the first TRP and thenon-participating target object, a distance between the UE and thenon-participating target object, the location of the first TRP, and thelocation of the UE, the second ellipse is determined based on a distancebetween the second TRP and the non-participating target object, thedistance between the UE and the non-participating target object, thelocation of the second TRP, and the location of the UE, and the thirdellipse is determined based on a distance between the third TRP and thenon-participating target object, the distance between the UE and thenon-participating target object, the location of the third TRP, and thelocation of the UE.
 5. The method of claim 4, wherein: the distancebetween the first TRP and the non-participating target object plus thedistance between the UE and the non-participating target object isdetermined based on the first RSTD, the distance between the second TRPand the non-participating target object plus the distance between the UEand the non-participating target object is determined based on thesecond RSTD, and the distance between the third TRP and thenon-participating target object plus the distance between the UE and thenon-participating target object is determined based on the third RSTD.6. The method of claim 3, wherein the location of the UE is determinedbased on an RSTD between the ToA of the LOS path of the first DL-PRS anda ToA of the LOS path of the second DL-PRS and an RSTD between the ToAof the LOS path of the first DL-PRS and a ToA of the LOS path of thethird DL-PRS.
 7. The method of claim 1, wherein enabling the location ofthe non-participating target object to be determined comprises:reporting, to a location server, at least a difference between thesecond RSTD and the first RSTD and a difference between the third RSTDand the first RSTD.
 8. The method of claim 1, wherein: the location ofthe non-participating target object is determined to be at anintersection of a first hyperbola, a second hyperbola, and a thirdhyperbola, a foci of the first hyperbola is a location of the first TRP,a foci of the second hyperbola is a location of the second TRP, and afoci of the third hyperbola is a location of the third TRP.
 9. Themethod of claim 8, wherein: the first hyperbola is determined based on adifference between a distance between the second TRP and thenon-participating target object and a distance between the first TRP andthe non-participating target object, the location of the first TRP, andthe location of the second TRP, the second hyperbola is determined basedon a difference between a distance between the third TRP and thenon-participating target object and the distance between the first TRPand the non-participating target object, the location of the first TRP,and the location of the third TRP, and the third hyperbola is determinedbased on a difference between the distance between the second TRP andthe non-participating target object and the distance between the thirdTRP and the non-participating target object, the location of the secondTRP, and the location of the third TRP.
 10. The method of claim 9,wherein the difference between the distance between the second TRP andthe non-participating target object and the distance between the firstTRP and the non-participating target object, the difference between thedistance between the third TRP and the non-participating target objectand the distance between the first TRP and the non-participating targetobject, and the difference between the distance between the second TRPand the non-participating target object and the distance between thethird TRP and the non-participating target object are determined basedon a difference between the second RSTD and the first RSTD and adifference between the third RSTD and the first RSTD.
 11. The method ofclaim 1, further comprising: reporting, to a location server, at leastan RSTD between the ToA of the LOS path of the first DL-PRS and a ToA ofthe LOS path of the second DL-PRS and an RSTD between the ToA of the LOSpath of the first DL-PRS and a ToA of the LOS path of the third DL-PRSto enable the location server to determine a location of the UE.
 12. Themethod of claim 1, wherein enabling the location of thenon-participating target object to be determined comprises: determiningthe location of the non-participating target object based on the firstRSTD between the ToA of the LOS path of the first DL-PRS and the ToA ofthe NLOS path of the first DL-PRS, the second RSTD between the ToA ofthe LOS path of the first DL-PRS and the ToA of the NLOS path of thesecond DL-PRS, and the third RSTD between the ToA of the LOS path of thefirst DL-PRS and the ToA of the NLOS path of the third DL-PRS.
 13. Themethod of claim 12, further comprising: receiving a location of thefirst TRP, a location of the second TRP, and a location of the thirdTRP, wherein determining the location of the non-participating targetobject is further based on the location of the first TRP, the locationof the second TRP, and the location of the third TRP.
 14. A userequipment (UE), comprising: a memory; at least one transceiver; and atleast one processor communicatively coupled to the memory and the atleast one transceiver, the at least one processor configured to: measureat least a line-of-sight (LOS) path and a non-line-of-sight (NLOS) pathof a first downlink positioning reference signal (DL-PRS) from a firsttransmission-reception point (TRP); measure at least an LOS path and anNLOS path of a second DL-PRS from a second TRP; measure at least an LOSpath and an NLOS path of a third DL-PRS from a third TRP; and enable alocation of a non-participating target object to be determined based, atleast in part, on a first reference signal time difference (RSTD)between a time of arrival (ToA) of the LOS path of the first DL-PRS anda ToA of the NLOS path of the first DL-PRS, a second RSTD between theToA of the LOS path of the first DL-PRS and a ToA of the NLOS path ofthe second DL-PRS, and a third RSTD between the ToA of the LOS path ofthe first DL-PRS and a ToA of the NLOS path of the third DL-PRS, whereinthe non-participating target object does not participate in determiningthe location of the non-participating target object.
 15. The UE of claim14, wherein the at least one processor configured to enable the locationof the non-participating target object to be determined comprises the atleast one processor configured to: report, to a location server, atleast the first RSTD, the second RSTD, and the third RSTD.
 16. The UE ofclaim 14, wherein: the location of the non-participating target objectis determined to be at an intersection of a first ellipse, a secondellipse, and a third ellipse, first and second foci of the first ellipsecorrespond to a location of the first TRP and a location of the UE,first and second foci of the second ellipse correspond to a location ofthe second TRP and the location of the UE, and first and second foci ofthe third ellipse correspond to a location of the third TRP and thelocation of the UE.
 17. The UE of claim 16, wherein: the first ellipseis determined based on a distance between the first TRP and thenon-participating target object, a distance between the UE and thenon-participating target object, the location of the first TRP, and thelocation of the UE, the second ellipse is determined based on a distancebetween the second TRP and the non-participating target object, thedistance between the UE and the non-participating target object, thelocation of the second TRP, and the location of the UE, and the thirdellipse is determined based on a distance between the third TRP and thenon-participating target object, the distance between the UE and thenon-participating target object, the location of the third TRP, and thelocation of the UE.
 18. The UE of claim 17, wherein: the distancebetween the first TRP and the non-participating target object plus thedistance between the UE and the non-participating target object isdetermined based on the first RSTD, the distance between the second TRPand the non-participating target object plus the distance between the UEand the non-participating target object is determined based on thesecond RSTD, and the distance between the third TRP and thenon-participating target object plus the distance between the UE and thenon-participating target object is determined based on the third RSTD.19. The UE of claim 16, wherein the location of the UE is determinedbased on an RSTD between the ToA of the LOS path of the first DL-PRS anda ToA of the LOS path of the second DL-PRS and an RSTD between the ToAof the LOS path of the first DL-PRS and a ToA of the LOS path of thethird DL-PRS.
 20. The UE of claim 14, wherein the at least one processorconfigured to enable the location of the non-participating target objectto be determined comprises the at least one processor configured to:report, to a location server, at least a difference between the secondRSTD and the first RSTD and a difference between the third RSTD and thefirst RSTD.
 21. The UE of claim 14, wherein: the location of thenon-participating target object is determined to be at an intersectionof a first hyperbola, a second hyperbola, and a third hyperbola, a fociof the first hyperbola is a location of the first TRP, a foci of thesecond hyperbola is a location of the second TRP, and a foci of thethird hyperbola is a location of the third TRP.
 22. The UE of claim 21,wherein: the first hyperbola is determined based on a difference betweena distance between the second TRP and the non-participating targetobject and a distance between the first TRP and the non-participatingtarget object, the location of the first TRP, and the location of thesecond TRP, the second hyperbola is determined based on a differencebetween a distance between the third TRP and the non-participatingtarget object and the distance between the first TRP and thenon-participating target object, the location of the first TRP, and thelocation of the third TRP, and the third hyperbola is determined basedon a difference between the distance between the second TRP and thenon-participating target object and the distance between the third TRPand the non-participating target object, the location of the second TRP,and the location of the third TRP.
 23. The UE of claim 22, wherein thedifference between the distance between the second TRP and thenon-participating target object and the distance between the first TRPand the non-participating target object, the difference between thedistance between the third TRP and the non-participating target objectand the distance between the first TRP and the non-participating targetobject, and the difference between the distance between the second TRPand the non-participating target object and the distance between thethird TRP and the non-participating target object are determined basedon a difference between the second RSTD and the first RSTD and adifference between the third RSTD and the first RSTD.
 24. The UE ofclaim 14, wherein the at least one processor is further configured to:report, to a location server, at least an RSTD between the ToA of theLOS path of the first DL-PRS and a ToA of the LOS path of the secondDL-PRS and an RSTD between the ToA of the LOS path of the first DL-PRSand a ToA of the LOS path of the third DL-PRS to enable the locationserver to determine a location of the UE.
 25. The UE of claim 14,wherein the at least one processor configured to enable the location ofthe non-participating target object to be determined comprises the atleast one processor configured to: determine the location of thenon-participating target object based on the first RSTD between the ToAof the LOS path of the first DL-PRS and the ToA of the NLOS path of thefirst DL-PRS, the second RSTD between the ToA of the LOS path of thefirst DL-PRS and the ToA of the NLOS path of the second DL-PRS, and thethird RSTD between the ToA of the LOS path of the first DL-PRS and theToA of the NLOS path of the third DL-PRS.
 26. The UE of claim 25,wherein the at least one processor is further configured to: receive,via the at least one transceiver, a location of the first TRP, alocation of the second TRP, and a location of the third TRP, whereindetermining the location of the non-participating target object isfurther based on the location of the first TRP, the location of thesecond TRP, and the location of the third TRP.
 27. A user equipment(UE), comprising: means for measuring at least a line-of-sight (LOS)path and a non-line-of-sight (NLOS) path of a first downlink positioningreference signal (DL-PRS) from a first transmission-reception point(TRP); means for measuring at least an LOS path and an NLOS path of asecond DL-PRS from a second TRP; means for measuring at least an LOSpath and an NLOS path of a third DL-PRS from a third TRP; and means forenabling a location of a non-participating target object to bedetermined based, at least in part, on a first reference signal timedifference (RSTD) between a time of arrival (ToA) of the LOS path of thefirst DL-PRS and a ToA of the NLOS path of the first DL-PRS, a secondRSTD between the ToA of the LOS path of the first DL-PRS and a ToA ofthe NLOS path of the second DL-PRS, and a third RSTD between the ToA ofthe LOS path of the first DL-PRS and a ToA of the NLOS path of the thirdDL-PRS, wherein the non-participating target object does not participatein determining the location of the non-participating target object. 28.The UE of claim 27, wherein: the location of the non-participatingtarget object is determined to be at an intersection of a first ellipse,a second ellipse, and a third ellipse, first and second foci of thefirst ellipse correspond to a location of the first TRP and a locationof the UE, first and second foci of the second ellipse correspond to alocation of the second TRP and the location of the UE, and first andsecond foci of the third ellipse correspond to a location of the thirdTRP and the location of the UE.
 29. The UE of claim 27, wherein: thelocation of the non-participating target object is determined to be atan intersection of a first hyperbola, a second hyperbola, and a thirdhyperbola, a foci of the first hyperbola is a location of the first TRP,a foci of the second hyperbola is a location of the second TRP, and afoci of the third hyperbola is a location of the third TRP.
 30. Anon-transitory computer-readable medium storing computer-executableinstructions that, when executed by a user equipment (UE), cause the UEto: measure at least a line-of-sight (LOS) path and a non-line-of-sight(NLOS) path of a first downlink positioning reference signal (DL-PRS)from a first transmission-reception point (TRP); measure at least an LOSpath and an NLOS path of a second DL-PRS from a second TRP; measure atleast an LOS path and an NLOS path of a third DL-PRS from a third TRP;and enable a location of a non-participating target object to bedetermined based, at least in part, on a first reference signal timedifference (RSTD) between a time of arrival (ToA) of the LOS path of thefirst DL-PRS and a ToA of the NLOS path of the first DL-PRS, a secondRSTD between the ToA of the LOS path of the first DL-PRS and a ToA ofthe NLOS path of the second DL-PRS, and a third RSTD between the ToA ofthe LOS path of the first DL-PRS and a ToA of the NLOS path of the thirdDL-PRS, wherein the non-participating target object does not participatein determining the location of the non-participating target object.